code: def test_get_indexer_base(self):
      # Determined by cat ordering.
      idx = CategoricalIndex(list("cab"), categories=list("cab"))
      expected = np.arange(len(idx), dtype=np.intp)
  
      actual = idx.get_indexer(idx)
      tm.assert_numpy_array_equal(expected, actual)
  
      with pytest.raises(ValueError, match="Invalid fill method"):
          idx.get_indexer(idx, method="invalid")
  
imports: import numpy
  import pytest
  from pandas.errors import InvalidIndexError
  import pandas
  from pandas import CategoricalIndex, Index, IntervalIndex, Timestamp
  import pandas._testing
label_desc: Use image node_id 1 for calling the TestGetIndexer obj's underlying member method code with example usage: obj.test_get_indexer_base() without return types