class_docstr: Calls :meth:`orion.core.io.database.AbstractDB.index_information`.
docstr: Test representation of compound indexes.
docstr_tok: ["Test","representation","of","compound","indexes","."]
code: def test_compound_index(self, orion_db, db_test_data):
      """Test representation of compound indexes."""
      unique, keys_pair, index_information = db_test_data
      orion_db.ensure_index(
          "experiments",
          keys_pair,
          unique=unique,
      )
  
      assert (
          orion_db.index_information("experiments") == index_information
      )
  
imports: import pickle
  from datetime import datetime
  import pytest
  from orion.core.io.database import Database, DatabaseError, DuplicateKeyError
  from orion.core.io.database.ephemeraldb import EphemeralDB
  from orion.core.io.database.mongodb import MongoDB
  from orion.core.io.database.pickleddb import PickledDB
  from .conftest import insert_test_collection
label_desc: Use image node_id 4 for calling the TestIndexInformation obj's underlying member method code with example usage: obj.test_compound_index(orion_db, db_test_data) without return types