code: def _generate_scitype_mtype_fixtureindex_combinations():
      """Return fixture tuples for pytest_generate_tests.
  
      Fixtures parameterized
      ----------------------
      scitype : str - scitype of fixture
      mtype : str - mtype of fixture
      fixture_index : int - index of fixture tuple with that scitype and mtype
      """
      # collect fixture tuples here
  
      sci_mtype_tuples = _generate_scitype_mtype_combinations()
  
      sci_mtype_index_tuples = []
  
      for tuple_j in sci_mtype_tuples:
          scitype = tuple_j[0]
          mtype = tuple_j[1]
          n_fixtures = len(
              get_examples(mtype=mtype, as_scitype=scitype)
          )
  
          for i in range(n_fixtures):
              if (
                  get_examples(mtype=mtype, as_scitype=scitype).get(i)
                  is not None
              ):
                  sci_mtype_index_tuples += [(scitype, mtype, i)]
  
      return sci_mtype_index_tuples
  
imports: import numpy
  import pandas
  import pytest
  from sktime.datatypes import MTYPE_REGISTER, SCITYPE_REGISTER
  from sktime.datatypes._check import AMBIGUOUS_MTYPES, check_is_mtype
  from sktime.datatypes._examples import get_examples
  from sktime.datatypes._vectorize import VectorizedDF, _enforce_index_freq
  from sktime.utils._testing.deep_equals import deep_equals
  from sktime.utils.pandas import df_map
  from sktime.utils.parallel import _get_parallel_test_fixtures
label_desc: Use image node_id 4 for calling a global function with example usage: _generate_scitype_mtype_fixtureindex_combinations() and returns: sci_mtype_index_tuples