code: def test_open(self):
      expected = 'start_key_open: "row1"\n' 'end_key_open: "row2"\n'
      self.assertEqual(
          expected, repr(row_range.open_range("row1", "row2"))
      )
  
imports: from tensorflow_io.python.ops import core_ops
  import tensorflow_io.python.ops.bigtable.bigtable_row_range
  import tensorflow_io.python.ops.bigtable.bigtable_row_set
  from tensorflow import test
label_desc: Use image node_id 8 for calling the RowRangeTest obj's underlying member method code with example usage: obj.test_open() without return types