code: public Set<String> getNotAttributeFields() {
  		Set<String> notAttributeFields = new HashSet<>();
  		for (ResourceField relationshipField : relationshipFields) {
  			notAttributeFields.add(relationshipField.getJsonName());
  		}
  		notAttributeFields.add(idField.getJsonName());
  		if (metaField != null) {
  			notAttributeFields.add(metaField.getUnderlyingName());
  		}
  		if (linksField != null) {
  			notAttributeFields.add(linksField.getUnderlyingName());
  		}
  		return notAttributeFields;
  	}
docs: Returns a set of field names which are not basic fields (resource
  attributes)
  
  @return not basic attribute names