def onShortcutUnindentWithBackspace(self):
        """Backspace pressed, unindent
        """
        assert self._qpart.textBeforeCursor().endswith(self.text())

        charsToRemove = len(self._qpart.textBeforeCursor()) % len(self.text())
        if charsToRemove == 0:
            charsToRemove = len(self.text())

        cursor = self._qpart.textCursor()
        cursor.setPosition(cursor.position() - charsToRemove, QTextCursor.KeepAnchor)
        cursor.removeSelectedText()
def test_config_errors(self):
        Session = scoped_session(sa.orm.sessionmaker())

        s = Session()  # noqa
        assert_raises_message(
            sa.exc.InvalidRequestError,
            "Scoped session is already present",
            Session,
            bind=testing.db,
        )

        assert_warns_message(
            sa.exc.SAWarning,
            "At least one scoped session is already present. ",
            Session.configure,
            bind=testing.db,
        )