code: def test_intersect(self, cases, test_length):
      xloc, xlen, yloc, ylen, eloc, elen = cases
      xindex = BlockIndex(test_length, xloc, xlen)
      yindex = BlockIndex(test_length, yloc, ylen)
      expected = BlockIndex(test_length, eloc, elen)
      longer_index = BlockIndex(test_length + 1, yloc, ylen)
  
      result = xindex.intersect(yindex)
      assert result.equals(expected)
      result = xindex.to_int_index().intersect(yindex.to_int_index())
      assert result.equals(expected.to_int_index())
  
      msg = "Indices must reference same underlying length"
      with pytest.raises(Exception, match=msg):
          xindex.intersect(longer_index)
      with pytest.raises(Exception, match=msg):
          xindex.to_int_index().intersect(longer_index.to_int_index())
  
imports: import operator
  import numpy
  import pytest
  import pandas._libs.sparse
  import pandas.util._test_decorators
  from pandas import Series
  import pandas._testing
  from pandas.core.arrays.sparse import BlockIndex, IntIndex, make_sparse_index
label_desc: Use image node_id 1 for calling the TestSparseIndexIntersect obj's underlying member method code with example usage: obj.test_intersect(cases, test_length) without return types