def _assert_fillna_conversion(self, original, value, expected, expected_dtype):
    'test coercion triggered by fillna'
    target = original.copy()
    res = target.fillna(value)
    tm.assert_equal(res, expected)
    assert (res.dtype == expected_dtype)
test coercion triggered by fillna
def _assert_fillna_conversion(self, original, value, expected, expected_dtype):
    
    target = original.copy()
    res = target.fillna(value)
    tm.assert_equal(res, expected)
    assert (res.dtype == expected_dtype)