code: public String setPropertyTypeFromEntityIdValue(
  			PropertyIdValue propertyIdValue, EntityIdValue value) {
  		switch (value.getId().charAt(0)) {
  		case 'Q':
  			return DatatypeIdValue.DT_ITEM;
  		case 'P':
  			return DatatypeIdValue.DT_PROPERTY;
  		default:
  			logger.warn("Could not determine Type of "
  					+ propertyIdValue.getId()
  					+ ". It is not a valid EntityDocument Id");
  			return null;
  		}
  	}
docs: Returns the IRI of the primitive Type of an Property for
  {@link EntityIdValue} objects.
  
  @param propertyIdValue
  @param value