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 __init__(self, table=None, n_classes=2, class_names=("1", "0")):
        self.table = table
        self.n_classes = n_classes
        self.class_names = class_names
        if table is None:
            self.table = np.zeros((self.n_classes, self.n_classes), dtype=int)