LaneBasedGTUGenerator.java
package org.opentrafficsim.road.gtu.generator;
import java.io.Serializable;
import java.rmi.RemoteException;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.Map;
import java.util.Queue;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import javax.media.j3d.Bounds;
import javax.naming.NamingException;
import org.djunits.unit.DurationUnit;
import org.djunits.value.vdouble.scalar.Duration;
import org.djunits.value.vdouble.scalar.Length;
import org.djunits.value.vdouble.scalar.Speed;
import org.djunits.value.vdouble.scalar.Time;
import org.djutils.event.EventProducer;
import org.djutils.event.EventType;
import org.djutils.exceptions.Throw;
import org.djutils.immutablecollections.ImmutableMap;
import org.opentrafficsim.base.Identifiable;
import org.opentrafficsim.base.TimeStampedObject;
import org.opentrafficsim.base.parameters.ParameterException;
import org.opentrafficsim.core.distributions.Generator;
import org.opentrafficsim.core.distributions.ProbabilityException;
import org.opentrafficsim.core.dsol.OTSSimulatorInterface;
import org.opentrafficsim.core.geometry.OTSGeometryException;
import org.opentrafficsim.core.gtu.GTUDirectionality;
import org.opentrafficsim.core.gtu.GTUErrorHandler;
import org.opentrafficsim.core.gtu.GTUException;
import org.opentrafficsim.core.gtu.GTUType;
import org.opentrafficsim.core.gtu.RelativePosition;
import org.opentrafficsim.core.idgenerator.IdGenerator;
import org.opentrafficsim.core.network.NetworkException;
import org.opentrafficsim.road.gtu.generator.GeneratorPositions.GeneratorLanePosition;
import org.opentrafficsim.road.gtu.generator.GeneratorPositions.GeneratorLinkPosition;
import org.opentrafficsim.road.gtu.generator.characteristics.LaneBasedGTUCharacteristics;
import org.opentrafficsim.road.gtu.generator.characteristics.LaneBasedGTUCharacteristicsGenerator;
import org.opentrafficsim.road.gtu.lane.LaneBasedGTU;
import org.opentrafficsim.road.gtu.lane.LaneBasedIndividualGTU;
import org.opentrafficsim.road.gtu.lane.perception.headway.HeadwayGTU;
import org.opentrafficsim.road.gtu.lane.perception.headway.HeadwayGTUReal;
import org.opentrafficsim.road.network.OTSRoadNetwork;
import org.opentrafficsim.road.network.lane.CrossSectionLink;
import org.opentrafficsim.road.network.lane.DirectedLanePosition;
import org.opentrafficsim.road.network.lane.Lane;
import org.opentrafficsim.road.network.lane.LaneDirection;
import nl.tudelft.simulation.dsol.SimRuntimeException;
import nl.tudelft.simulation.language.d3.DirectedPoint;
/**
* Lane based GTU generator. This generator generates lane based GTUs using a LaneBasedTemplateGTUType. The template is used to
* generate a set of GTU characteristics at the times implied by the headway generator. These sets are queued until there is
* sufficient room to construct a GTU at the specified lane locations. The speed of a construction GTU may be reduced to ensure
* it does not run into its immediate leader GTU.
* <p>
* Copyright (c) 2013-2020 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
* BSD-style license. See <a href="http://opentrafficsim.org/docs/current/license.html">OpenTrafficSim License</a>.
* <p>
* @version $Revision$, $LastChangedDate$, by $Author$, initial version Mar 8, 2016 <br>
* @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
* @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
*/
public class LaneBasedGTUGenerator extends EventProducer implements Serializable, Identifiable, GtuGeneratorQueue
{
/** */
private static final long serialVersionUID = 20160000L;
/**
* Event of a generated GTU. Payload: LaneBasedIndividualGTU
*/
public static final EventType GTU_GENERATED_EVENT = new EventType("GENERATOR.GTU_GENERATED");
/** FIFO for templates that have not been generated yet due to insufficient room/headway, per position, and per link. */
private final Map<CrossSectionLink, Map<GeneratorLanePosition, Queue<TimeStampedObject<LaneBasedGTUCharacteristics>>>> unplacedTemplates =
new LinkedHashMap<>();
/** Name of the GTU generator. */
private final String id;
/** Time distribution that determines the interval times between GTUs. */
private final Generator<Duration> interarrivelTimeGenerator;
/** Generates most properties of the GTUs. */
private final LaneBasedGTUCharacteristicsGenerator laneBasedGTUCharacteristicsGenerator;
/** Total number of GTUs generated so far. */
private long generatedGTUs = 0;
/** Retry interval for checking if a GTU can be placed. */
private Duration reTryInterval = new Duration(0.1, DurationUnit.SI);
/** Location and initial direction provider for all generated GTUs. */
private final GeneratorPositions generatorPositions;
/** Network. */
private final OTSRoadNetwork network;
/** Simulator. */
private final OTSSimulatorInterface simulator;
/** The way that this generator checks if it is safe to construct and place the next lane based GTU. */
private final RoomChecker roomChecker;
/** ID generator. */
private final IdGenerator idGenerator;
/** Initial distance over which lane changes shouldn't be performed. */
private Length noLaneChangeDistance = null;
/** Whether GTUs change lane instantaneously. */
private boolean instantaneousLaneChange = false;
/** GTU error handler. */
private GTUErrorHandler errorHandler = GTUErrorHandler.THROW;
/** Vehicle generation is ignored on these lanes. */
private Set<LaneDirection> disabled = new LinkedHashSet<>();
/**
* Construct a new lane base GTU generator.
* @param id String; name of the new GTU generator
* @param interarrivelTimeGenerator Generator<Duration>; generator for the interval times between GTUs
* @param laneBasedGTUCharacteristicsGenerator LaneBasedGTUCharacteristicsGenerator; generator of the characteristics of
* each GTU
* @param generatorPositions GeneratorPositions; location and initial direction provider for all generated GTUs
* @param network OTSRoadNetwork; the OTS network that owns the generated GTUs
* @param simulator OTSSimulatorInterface; simulator
* @param roomChecker RoomChecker; the way that this generator checks that there is sufficient room to place a new GTU
* @param idGenerator IdGenerator; id generator
* @throws SimRuntimeException when <cite>startTime</cite> lies before the current simulation time
* @throws ProbabilityException pe
* @throws ParameterException if drawing from the interarrival generator fails
*/
@SuppressWarnings("parameternumber")
public LaneBasedGTUGenerator(final String id, final Generator<Duration> interarrivelTimeGenerator,
final LaneBasedGTUCharacteristicsGenerator laneBasedGTUCharacteristicsGenerator,
final GeneratorPositions generatorPositions, final OTSRoadNetwork network, final OTSSimulatorInterface simulator,
final RoomChecker roomChecker, final IdGenerator idGenerator) throws SimRuntimeException, ProbabilityException,
ParameterException
{
this.id = id;
this.interarrivelTimeGenerator = interarrivelTimeGenerator;
this.laneBasedGTUCharacteristicsGenerator = laneBasedGTUCharacteristicsGenerator;
this.generatorPositions = generatorPositions;
this.network = network;
this.simulator = simulator;
this.roomChecker = roomChecker;
this.idGenerator = idGenerator;
Duration headway = this.interarrivelTimeGenerator.draw();
if (headway != null) // otherwise no demand at all
{
simulator.scheduleEventRel(headway, this, this, "generateCharacteristics", new Object[] {});
}
}
/**
* Sets the initial distance over which lane changes shouldn't be performed.
* @param noLaneChangeDistance Length; initial distance over which lane changes shouldn't be performed
*/
public void setNoLaneChangeDistance(final Length noLaneChangeDistance)
{
this.noLaneChangeDistance = noLaneChangeDistance;
}
/**
* Sets whether GTUs will change lane instantaneously.
* @param instantaneous boolean; whether GTUs will change lane instantaneously
*/
public void setInstantaneousLaneChange(final boolean instantaneous)
{
this.instantaneousLaneChange = instantaneous;
}
/**
* Sets the GTU error handler.
* @param gtuErrorHandler GTUErrorHandler; GTU error handler
*/
public void setErrorHandler(final GTUErrorHandler gtuErrorHandler)
{
this.errorHandler = gtuErrorHandler;
}
/**
* Generate the characteristics of the next GTU.
* @throws ProbabilityException when something is wrongly defined in the LaneBasedTemplateGTUType
* @throws SimRuntimeException when this method fails to re-schedule itself or the call to the method that tries to place a
* GTU on the road
* @throws ParameterException in case of a parameter problem
* @throws GTUException if strategical planner cannot generate a plan
*/
@SuppressWarnings("unused")
private void generateCharacteristics() throws ProbabilityException, SimRuntimeException, ParameterException, GTUException
{
synchronized (this.unplacedTemplates)
{
LaneBasedGTUCharacteristics characteristics = this.laneBasedGTUCharacteristicsGenerator.draw();
GTUType gtuType = characteristics.getGTUType();
// gather information on number of unplaced templates per lane, and per link, for the drawing of a new position
Map<CrossSectionLink, Map<Integer, Integer>> unplaced = new LinkedHashMap<>();
for (CrossSectionLink link : this.unplacedTemplates.keySet())
{
Map<Integer, Integer> linkMap = new LinkedHashMap<>();
Map<GeneratorLanePosition, Queue<TimeStampedObject<LaneBasedGTUCharacteristics>>> linkTemplates =
this.unplacedTemplates.get(link);
for (GeneratorLanePosition lanePosition : linkTemplates.keySet())
{
linkMap.put(lanePosition.getLaneNumber(), linkTemplates.get(lanePosition).size());
}
unplaced.put(link, linkMap);
}
// position draw
GeneratorLinkPosition linkPosition = this.generatorPositions.draw(gtuType, characteristics.getDestination(),
characteristics.getRoute());
Speed desiredSpeed = characteristics.getStrategicalPlannerFactory().peekDesiredSpeed(gtuType, linkPosition
.speedLimit(gtuType), characteristics.getMaximumSpeed());
GeneratorLanePosition lanePosition = linkPosition.draw(gtuType, unplaced.get(linkPosition.getLink()),
desiredSpeed);
// skip if disabled at this lane-direction
Set<LaneDirection> lanes = new LinkedHashSet<>();
for (DirectedLanePosition pos : lanePosition.getPosition())
{
lanes.add(pos.getLaneDirection());
}
if (Collections.disjoint(this.disabled, lanes))
{
queueGtu(lanePosition, characteristics);
}
}
Duration headway = this.interarrivelTimeGenerator.draw();
if (headway != null)
{
this.simulator.scheduleEventRel(headway, this, this, "generateCharacteristics", new Object[] {});
}
}
/**
* Check if the queue is non-empty and, if it is, try to place the GTUs in the queue on the road.
* @param position GeneratorLanePosition; position
* @throws SimRuntimeException should never happen
* @throws GTUException when something wrong in the definition of the GTU
* @throws OTSGeometryException when something is wrong in the definition of the GTU
* @throws NetworkException when something is wrong with the initial location of the GTU
* @throws NamingException ???
* @throws ProbabilityException pe
*/
@SuppressWarnings("unused")
private void tryToPlaceGTU(final GeneratorLanePosition position) throws SimRuntimeException, GTUException,
NamingException, NetworkException, OTSGeometryException, ProbabilityException
{
TimeStampedObject<LaneBasedGTUCharacteristics> timedCharacteristics;
Queue<TimeStampedObject<LaneBasedGTUCharacteristics>> queue = this.unplacedTemplates.get(position.getLink()).get(
position);
synchronized (queue)
{
timedCharacteristics = queue.peek();
}
if (null == timedCharacteristics)
{
return; // Do not re-schedule this method
}
LaneBasedGTUCharacteristics characteristics = timedCharacteristics.getObject();
SortedSet<HeadwayGTU> leaders = new TreeSet<>();
for (DirectedLanePosition dirPos : position.getPosition())
{
getFirstLeaders(dirPos.getLaneDirection(), dirPos.getPosition().neg().minus(characteristics.getFront()), dirPos
.getPosition(), leaders);
}
Duration since = this.simulator.getSimulatorTime().minus(timedCharacteristics.getTimestamp());
Placement placement = this.roomChecker.canPlace(leaders, characteristics, since, position.getPosition());
if (placement.canPlace())
{
// There is enough room; remove the template from the queue and construct the new GTU
synchronized (queue)
{
queue.remove();
}
placeGtu(characteristics, placement.getPosition(), placement.getSpeed());
if (queue.size() > 0)
{
this.simulator.scheduleEventNow(this, this, "tryToPlaceGTU", new Object[] {position});
}
}
else if (queue.size() > 0)
{
this.simulator.scheduleEventRel(this.reTryInterval, this, this, "tryToPlaceGTU", new Object[] {position});
}
}
/**
* Adds a GTU to the generation queue. This method ignores whether vehicle generation is enabled at the location. This
* allows an external party to govern (over some time) what vehicles are generated.
* @param characteristics LaneBasedGTUCharacteristics; characteristics of GTU to add to the queue
* @param position Set<LaneDirection>; position to generate the GTU at
*/
public final void queueGtu(final LaneBasedGTUCharacteristics characteristics, final Set<LaneDirection> position)
{
// first find the correct GeneratorLanePosition
GeneratorLanePosition genPosition = null;
Set<LaneDirection> genSet = new LinkedHashSet<>();
for (GeneratorLanePosition lanePosition : this.generatorPositions.getAllPositions())
{
for (DirectedLanePosition dirPos : lanePosition.getPosition())
{
genSet.add(dirPos.getLaneDirection());
}
if (genSet.equals(position))
{
genPosition = lanePosition;
break;
}
genSet.clear();
}
Throw.when(genPosition == null, IllegalStateException.class, "Position %s is not part of the generation.", position);
try
{
queueGtu(genPosition, characteristics);
}
catch (SimRuntimeException exception)
{
throw new RuntimeException("Unexpected exception while scheduling tryToPlace event.", exception);
}
}
/**
* Places the characteristics in the queue pertaining to the position, and schedules a call to {@code tryToPlace} now if the
* queue length is 1.
* @param lanePosition GeneratorLanePosition; position to generate the GTU at
* @param characteristics LaneBasedGTUCharacteristics; characteristics of GTU to add to the queue
* @throws SimRuntimeException when an event is scheduled in the past
*/
private void queueGtu(final GeneratorLanePosition lanePosition, final LaneBasedGTUCharacteristics characteristics)
throws SimRuntimeException
{
if (!this.unplacedTemplates.containsKey(lanePosition.getLink()))
{
this.unplacedTemplates.put(lanePosition.getLink(), new LinkedHashMap<>());
}
Map<GeneratorLanePosition, Queue<TimeStampedObject<LaneBasedGTUCharacteristics>>> linkMap = this.unplacedTemplates
.get(lanePosition.getLink());
if (!linkMap.containsKey(lanePosition))
{
linkMap.put(lanePosition, new LinkedList<>());
}
Queue<TimeStampedObject<LaneBasedGTUCharacteristics>> queue = linkMap.get(lanePosition);
queue.add(new TimeStampedObject<>(characteristics, this.simulator.getSimulatorTime()));
if (queue.size() == 1)
{
this.simulator.scheduleEventNow(this, this, "tryToPlaceGTU", new Object[] {lanePosition});
}
}
/**
* Places a GTU, regardless of whether it has room. The user of this method should verify this is the case.
* @param characteristics LaneBasedGTUCharacteristics; characteristics
* @param position Set<DirectedLanePosition>; position
* @param speed Speed; speed
* @throws NamingException on exception
* @throws GTUException on exception
* @throws NetworkException on exception
* @throws SimRuntimeException on exception
* @throws OTSGeometryException on exception
*/
public final void placeGtu(final LaneBasedGTUCharacteristics characteristics, final Set<DirectedLanePosition> position,
final Speed speed) throws NamingException, GTUException, NetworkException, SimRuntimeException,
OTSGeometryException
{
String gtuId = this.idGenerator.nextId();
LaneBasedIndividualGTU gtu = new LaneBasedIndividualGTU(gtuId, characteristics.getGTUType(), characteristics
.getLength(), characteristics.getWidth(), characteristics.getMaximumSpeed(), characteristics.getFront(),
this.simulator, this.network);
gtu.setMaximumAcceleration(characteristics.getMaximumAcceleration());
gtu.setMaximumDeceleration(characteristics.getMaximumDeceleration());
gtu.setVehicleModel(characteristics.getVehicleModel());
gtu.setNoLaneChangeDistance(this.noLaneChangeDistance);
gtu.setInstantaneousLaneChange(this.instantaneousLaneChange);
gtu.setErrorHandler(this.errorHandler);
gtu.init(characteristics.getStrategicalPlannerFactory().create(gtu, characteristics.getRoute(), characteristics
.getOrigin(), characteristics.getDestination()), position, speed);
this.generatedGTUs++;
fireEvent(GTU_GENERATED_EVENT, gtu);
}
/**
* Adds the first GTU on the lane to the set, or any number or leaders on downstream lane(s) if there is no GTU on the lane.
* @param lane LaneDirection; lane to search on
* @param startDistance Length; distance from generator location (nose) to start of the lane
* @param beyond Length; location to search downstream of which is the generator position, or the start for downstream lanes
* @param set Set<HeadwayGTU>; set to add the GTU's to
* @throws GTUException if a GTU is incorrectly positioned on a lane
*/
private void getFirstLeaders(final LaneDirection lane, final Length startDistance, final Length beyond,
final Set<HeadwayGTU> set) throws GTUException
{
LaneBasedGTU next = lane.getLane().getGtuAhead(beyond, lane.getDirection(), RelativePosition.FRONT, this.simulator
.getSimulatorTime());
if (next != null)
{
Length headway;
if (lane.getDirection().isPlus())
{
headway = startDistance.plus(next.position(lane.getLane(), next.getRear()));
}
else
{
headway = startDistance.plus(lane.getLane().getLength().minus(next.position(lane.getLane(), next
.getRear())));
}
if (headway.si < 300)
{
set.add(new HeadwayGTUReal(next, headway, true));
}
return;
}
ImmutableMap<Lane, GTUDirectionality> downstreamLanes = lane.getLane().downstreamLanes(lane.getDirection(),
this.network.getGtuType(GTUType.DEFAULTS.VEHICLE));
for (Lane downstreamLane : downstreamLanes.keySet())
{
Length startDistanceDownstream = startDistance.plus(lane.getLane().getLength());
if (startDistanceDownstream.si > 300)
{
return;
}
GTUDirectionality dir = downstreamLanes.get(downstreamLane);
Length beyondDownstream = dir.isPlus() ? Length.ZERO : downstreamLane.getLength();
getFirstLeaders(new LaneDirection(downstreamLane, dir), startDistanceDownstream, beyondDownstream, set);
}
}
/** {@inheritDoc} */
@Override
public final String toString()
{
return "LaneBasedGTUGenerator " + this.id + " on " + this.generatorPositions;
}
/**
* @return generatedGTUs.
*/
public final long getGeneratedGTUs()
{
return this.generatedGTUs;
}
/**
* Retrieve the id of this LaneBasedGTUGenerator.
* @return String; the id of this LaneBasedGTUGenerator
*/
@Override
public final String getId()
{
return this.id;
}
/**
* Disable the vehicle generator during the specific time. Underlying processes such as drawing characteristics and headways
* are continued, but simply will not result in the queuing of the GTU.
* @param start Time; start time
* @param end Time; end time
* @param laneDirections Set<LaneDirection>; lanes to disable generation on
* @throws SimRuntimeException if time is incorrect
*/
public void disable(final Time start, final Time end, final Set<LaneDirection> laneDirections) throws SimRuntimeException
{
Throw.when(end.lt(start), SimRuntimeException.class, "End time %s is before start time %s.", end, start);
this.simulator.scheduleEventAbs(start, this, this, "disable", new Object[] {laneDirections});
this.simulator.scheduleEventAbs(end, this, this, "enable", new Object[0]);
}
/**
* Disables the generator.
* @param laneDirections Set<LaneDirection>; lanes to disable generation on
*/
@SuppressWarnings("unused")
private void disable(final Set<LaneDirection> laneDirections)
{
Throw.when(this.disabled != null && !this.disabled.isEmpty(), IllegalStateException.class,
"Disabling a generator that is already disabled is not allowed.");
this.disabled = laneDirections;
}
/**
* Enables the generator.
*/
@SuppressWarnings("unused")
private void enable()
{
this.disabled = new LinkedHashSet<>();
}
/**
* Interface for class that checks that there is sufficient room for a proposed new GTU and returns the maximum safe speed
* and position for the proposed new GTU.
*/
public interface RoomChecker
{
/**
* Return the maximum safe speed and position for a new GTU with the specified characteristics. Returns
* {@code Placement.NO} if there is no safe speed and position. This method might be called with an empty leader set
* such that the desired speed can be implemented.
* @param leaders SortedSet<HeadwayGTU>; leaders, usually 1, possibly more after a branch
* @param characteristics LaneBasedGTUCharacteristics; characteristics of the proposed new GTU
* @param since Duration; time since the GTU wanted to arrive
* @param initialPosition Set<DirectedLanePosition>; initial position
* @return Speed; maximum safe speed, or null if a GTU with the specified characteristics cannot be placed at the
* current time
* @throws NetworkException this method may throw a NetworkException if it encounters an error in the network structure
* @throws GTUException on parameter exception
*/
Placement canPlace(SortedSet<HeadwayGTU> leaders, LaneBasedGTUCharacteristics characteristics, Duration since,
Set<DirectedLanePosition> initialPosition) throws NetworkException, GTUException;
}
/**
* Placement contains the information that a {@code RoomChecker} returns.
* <p>
* Copyright (c) 2013-2020 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
* <br>
* BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
* <p>
* @version $Revision$, $LastChangedDate$, by $Author$, initial version 12 jan. 2018 <br>
* @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
* @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
* @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
*/
public static final class Placement
{
/** Value if the GTU cannot be placed. */
public static final Placement NO = new Placement();
/** Speed. */
private final Speed speed;
/** Position. */
private final Set<DirectedLanePosition> position;
/**
* Constructor for NO.
*/
private Placement()
{
this.speed = null;
this.position = null;
}
/**
* Constructor.
* @param speed Speed; speed
* @param position Set<DirectedLanePosition>; position
*/
public Placement(final Speed speed, final Set<DirectedLanePosition> position)
{
Throw.whenNull(speed, "Speed may not be null. Use Placement.NO if the GTU cannot be placed.");
Throw.whenNull(position, "Position may not be null. Use Placement.NO if the GTU cannot be placed.");
this.speed = speed;
this.position = position;
}
/**
* Returns whether the GTU can be placed.
* @return whether the GTU can be placed
*/
public boolean canPlace()
{
return this.speed != null && this.position != null;
}
/**
* Returns the speed.
* @return Speed; speed
*/
public Speed getSpeed()
{
return this.speed;
}
/**
* Returns the position.
* @return Set<DirectedLanePosition>; position
*/
public Set<DirectedLanePosition> getPosition()
{
return this.position;
}
/** {@inheritDoc} */
@Override
public String toString()
{
return "Placement [speed=" + this.speed + ", position=" + this.position + "]";
}
}
/** {@inheritDoc} */
@Override
public DirectedPoint getLocation() throws RemoteException
{
return this.generatorPositions.getLocation();
}
/** {@inheritDoc} */
@Override
public Bounds getBounds() throws RemoteException
{
return this.generatorPositions.getBounds();
}
/** {@inheritDoc} */
@Override
public Map<DirectedPoint, Integer> getQueueLengths()
{
Map<DirectedPoint, Integer> result = new LinkedHashMap<>();
for (CrossSectionLink link : this.unplacedTemplates.keySet())
{
for (GeneratorLanePosition lanePosition : this.unplacedTemplates.get(link).keySet())
{
result.put(lanePosition.getPosition().iterator().next().getLocation(), this.unplacedTemplates.get(link).get(
lanePosition).size());
}
}
for (GeneratorLanePosition lanePosition : this.generatorPositions.getAllPositions())
{
DirectedPoint p = lanePosition.getPosition().iterator().next().getLocation();
if (!result.containsKey(p))
{
result.put(p, 0);
}
}
return result;
}
/** {@inheritDoc} */
@Override
public Serializable getSourceId()
{
return this.id;
}
}