code: public <ValueType> ValueType getProperty( Property propertyId,
                                                Class<ValueType> type ) {
          return nodeProperties != null ? type.cast(nodeProperties.get(propertyId)) : null;
      }
docs: Get the node's value for this supplied property, casting the result to the supplied type.
  
  @param <ValueType> the type of the value expected
  @param propertyId the property identifier
  @param type the class denoting the type of value expected; may not be null
  @return the value, or null if there is no property on this node