def cursorAtSpaceEnd(block):
            cursor = QTextCursor(block)
            cursor.setPosition(block.position() + len(blockIndentation(block)))
            return cursor
def test_impl():
            A = np.array([1., 2., 3.])
            A[0] = np.nan
            df = pd.DataFrame({'A': A})
            df.A.fillna(5.0, inplace=True)
            return df.A.sum()