code: def test_duplicate_columns(self):
      df = pd.DataFrame(
          [[1, "a"], [2, "b"]], columns=["col_1", "col_1"]
      )
  
      expected_message = (
          "Yikes, plotly grids currently "
          "can't have duplicate column names. Rename "
          'the column "{}" and try again.'.format("col_1")
      )
  
      with self.assertRaisesRegex(InputError, expected_message):
          Grid(df)
  
imports: from __future__ import absolute_import
  from unittest import TestCase
  from chart_studio.exceptions import InputError
  from chart_studio.grid_objs import Grid
  import pandas
label_desc: Use image node_id 1 for calling the TestDataframeToGrid obj's underlying member method code with example usage: obj.test_duplicate_columns() without return types