namespace java eu.dnetlib.functionality.index.thrift exception InvalidOperation { 1: string why, 2: string details } service IndexService { binary indexLookup(1: string id, 2: string query, 3: string mdformat, 4: string layout) throws (1: InvalidOperation e), binary getBrowsingStatistics(1: string query, 2: string index, 3: string mdformat, 4: string layout) throws (1: InvalidOperation e), binary getNumberOfElements(1: string id) throws (1: InvalidOperation e), binary getResult(1: string id, 2: i32 fromPosition, 3: i32 toPosition) throws (1: InvalidOperation e) }