'Overlay(hint1, hint2) should populate hint2 with the values of hint1.'

def testCheckOverlay(self):

    full = {'problem': 'Terminator    needs    trousers.\n', 'fix': 'Give    me    your    clothes.\n', 'format': '{mission},    {target}\n', 'summary': "I'll    be    back."}
    partial = {'problem': 'Terminator    needs    to    go    shopping.', 'fix': 'Phased    plasma    rifle    in    the    40-watt    range.', 'format': '', 'summary': ''}
    overlay = {'problem': 'Terminator    needs    to    go    shopping.', 'fix': 'Phased    plasma    rifle    in    the    40-watt    range.', 'format': '{mission},    {target}', 'summary': "I'll    be    back."}
    empty = {'problem': '', 'fix': '', 'format': '', 'summary': ''}
    starts_full = full.copy()
    starts_empty = empty.copy()
    hints.Overlay(starts_full, starts_empty)
    self.assertDictEqual(full, starts_full)
    self.assertDictEqual(empty, starts_empty)
    starts_partial = partial.copy()
    starts_empty = empty.copy()
    hints.Overlay(starts_empty, starts_partial)
    self.assertDictEqual(partial, starts_partial)
    self.assertDictEqual(partial, starts_empty)
    starts_full = full.copy()
    starts_partial = partial.copy()
    hints.Overlay(starts_partial, starts_full)
    self.assertDictEqual(full, starts_full)
    self.assertDictEqual(overlay, starts_partial)
