old_contents: # -*- coding: utf-8 -*-
  # Copyright (c) 2015-2020, Exa Analytics Development Team
  # Distributed under the terms of the Apache License 2.0
  import pytest
  from exa.core.error import ExaException, RequiredColumnError
  
  
  def test_exceptions():
      e = ExaException("test")
      assert "test" in str(e)
      e = RequiredColumnError("col", "DataFrame")
      assert RequiredColumnError._msg.format("col", "DataFrame") == str(e)
  
new_contents: # -*- coding: utf-8 -*-
  # Copyright (c) 2015-2020, Exa Analytics Development Team
  # Distributed under the terms of the Apache License 2.0
  from exa.core.error import ExaException, RequiredColumnError
  
  
  def test_exceptions():
      e = ExaException("test")
      assert "test" in str(e)
      e = RequiredColumnError("col", "DataFrame")
      assert RequiredColumnError._msg.format("col", "DataFrame") == str(e)
  
subject: Remove unused import