code: public ExtendedRelation addSimpleAttributesRelationship(
  			String baseTableName, SimpleAttributesTable simpleAttributesTable,
  			String mappingTableName) {
  		return addRelationship(baseTableName, simpleAttributesTable,
  				mappingTableName);
  	}
docs: Adds a simple attributes relationship between the base table and user
  simple attributes related table. Creates a default user mapping table and
  the simple attributes table if needed.
  
  @param baseTableName
  base table name
  @param simpleAttributesTable
  user simple attributes table
  @param mappingTableName
  user mapping table name
  @return The relationship that was added