'Test the _extract_filter_tokens() method'

def test_extract_filter_tokens(self):

    testcases = [[None, []], ['', []], ['0    <        2001', ['0', '<', '2001']], ['x    <        2000', ['x', '<', '2000']], ['x    >        2000', ['x', '>', '2000']], ['x    ==    2000', ['x', '==', '2000']], ['x    >        2000    and    x    <        5000', ['x', '>', '2000', 'and', 'x', '<', '5000']], ['x    =    "goo"', ['x', '=', 'goo']], ['x    =    moo', ['x', '=', 'moo']], ['x    =    "foo    baz"', ['x', '=', 'foo    baz']], ['x    =    "moo    ""    bar"', ['x', '=', 'moo    "    bar']], ['x    =    "foo    bar"    or    x    =    "bar    foo"', ['x', '=', 'foo    bar', 'or', 'x', '=', 'bar    foo']], ['x    =    "foo    ""    bar"    or    x    =    "bar    ""    foo"', ['x', '=', 'foo    "    bar', 'or', 'x', '=', 'bar    "    foo']], ['x    =    """"""""', ['x', '=', '"""']], ['x    =    Blanks', ['x', '=', 'Blanks']], ['x    =    NonBlanks', ['x', '=', 'NonBlanks']], ['top    10    %', ['top', '10', '%']], ['top    10    items', ['top', '10', 'items']]]
    for testcase in testcases:
        expression = testcase[0]
        exp = testcase[1]
        got = self.worksheet._extract_filter_tokens(expression)
        self.assertEqual(got, exp)
