code: public Touple<SQLProperty, String, SQLiteEntity, SQLRelationType> findRelationByParentProperty(
  			String parentFieldName) {
  		for (Touple<SQLProperty, String, SQLiteEntity, SQLRelationType> item : relations) {
  			if (item.value0.getName().equals(parentFieldName)) {
  				return item;
  			}
  		}
  
  		return null;
  	}
docs: find a relation specifing parent field name, that is the name of the
  relation
  
  @param parentFieldName
  @return