code: public static String getTypeString(XAttribute attribute) {
  		if (attribute instanceof XAttributeList) {
  			return "LIST";
  		} else if (attribute instanceof XAttributeContainer) {
  			return "CONTAINER";
  		} else if (attribute instanceof XAttributeLiteral) {
  			return "LITERAL";
  		} else if (attribute instanceof XAttributeBoolean) {
  			return "BOOLEAN";
  		} else if (attribute instanceof XAttributeContinuous) {
  			return "CONTINUOUS";
  		} else if (attribute instanceof XAttributeDiscrete) {
  			return "DISCRETE";
  		} else if (attribute instanceof XAttributeTimestamp) {
  			return "TIMESTAMP";
  		} else if (attribute instanceof XAttributeID) {
  			return "ID";
  		} else {
  			throw new AssertionError("Unexpected attribute type!");
  		}
  	}
docs: For the given attribute, derives the standardized string describing the
  attributes specific type (used, e.g., for serialization).
  
  @param attribute
  Attribute to extract type string from.
  @return String representation of the attribute's specific type.