old_contents: #!/usr/bin/env python
  # encoding: utf-8
  import datetime
  import unittest
  
  import mock
  
  from nose.tools import assert_equal
  from pandas_finance import get_stock, get_required_tickers
  
  class PandasFinanceTestCase(unittest.TestCase):
      @mock.patch('pandas_finance.web.DataReader')
      def test_get_stock_called_correctly(self, mock_datareader):
          mock_datareader()
          start = datetime.datetime(1999, 4, 3, 0, 0)
          end = datetime.datetime(2005, 2, 5, 0, 0)
          get_stock('AAPL', start, end)
          mock_datareader.assert_called_with('AAPL', 'yahoo', start, end)
  
      def test_get_required_tickers_parses_tickers_with_newline(self):
          m = mock.mock_open(read_data='TWTR,FB,AAPL,MSFT\n')
          textfile = None  # only used to provide valid argument
          with mock.patch('pandas_finance.open', m, create=True):
              result = get_required_tickers(textfile)
          assert_equal('TWTR,FB,AAPL,MSFT', result)
  
new_contents: #!/usr/bin/env python
  # encoding: utf-8
  import datetime
  import unittest
  
  import mock
  
  from nose.tools import assert_equal
  from pandas_finance import get_stock, get_required_tickers
  
  class PandasFinanceTestCase(unittest.TestCase):
      @mock.patch('pandas_finance.web.DataReader')
      def test_get_stock_called_correctly(self, mock_datareader):
          start = datetime.datetime(1999, 4, 3, 0, 0)
          end = datetime.datetime(2005, 2, 5, 0, 0)
          get_stock('AAPL', start, end)
          mock_datareader.assert_called_with('AAPL', 'yahoo', start, end)
  
      def test_get_required_tickers_parses_tickers_with_newline(self):
          m = mock.mock_open(read_data='TWTR,FB,AAPL,MSFT\n')
          textfile = None  # only used to provide valid argument
          with mock.patch('pandas_finance.open', m, create=True):
              result = get_required_tickers(textfile)
          assert_equal('TWTR,FB,AAPL,MSFT', result)
  
subject: Remove unnecessary call to mock_datareader().