code: public static PropertyDocumentBuilder forPropertyIdAndDatatype(
  			PropertyIdValue propertyIdValue, String datatypeId) {
  		return forPropertyIdAndDatatype(propertyIdValue,
  				factory.getDatatypeIdValue(datatypeId));
  	}
docs: Starts the construction of an {@link PropertyDocument} with the given id.
  
  @param propertyIdValue
  id of the newly constructed property document
  @param datatypeId
  the datatype id of the newly constructed property document,
  e.g., {@link DatatypeIdValue#DT_ITEM}.
  @return builder object to continue construction