code: public ObjectTypeNodeMemory createMemory(final RuleBaseConfiguration config, InternalWorkingMemory wm) {
          Class<?> classType = ((ClassObjectType) getObjectType()).getClassType();
          if (InitialFact.class.isAssignableFrom(classType)) {
              return new InitialFactObjectTypeNodeMemory(classType);
          }
          return new ObjectTypeNodeMemory(classType, wm);
      }
docs: Creates memory for the node using PrimitiveLongMap as its optimised for storage and reteivals of Longs.
  However PrimitiveLongMap is not ideal for spase data. So it should be monitored incase its more optimal
  to switch back to a standard HashMap.