OOM in Postman heap space

Exception in thread "NetworkClientManagerRead" Exception in thread "Thread-1" java.lang.OutOfMemoryError: Java heap space
at java.util.Collections.unmodifiableList(Collections.java:1133)
at marauroa.common.game.RPObject.events(RPObject.java:508)
at games.stendhal.bot.postman.PostmanMain$1.onPerception(PostmanMain.java:109)
at marauroa.client.ClientFramework.loop(ClientFramework.java:608)
at games.stendhal.bot.postman.PostmanMain.run(PostmanMain.java:188)
java.lang.OutOfMemoryError: Java heap space
at marauroa.common.game.RPObject.clear(RPObject.java:118)
at marauroa.common.game.RPObject.<init>(RPObject.java:108)
at marauroa.common.net.message.MessageS2CPerception.readObject(MessageS2CPerception.java:264)
at marauroa.common.net.MessageFactory.getMessage(MessageFactory.java:213)
at marauroa.common.net.Decoder.decode(Decoder.java:241)
at marauroa.client.net.TCPNetworkClientManager$NetworkClientManagerRead.storeMessage(TCPNetworkClientManager.java:282)
at marauroa.client.net.TCPNetworkClientManager$NetworkClientManagerRead.run(TCPNetworkClientManager.java:387)