def unIndentBlock(block):
            currentIndent = blockIndentation(block)

            if currentIndent.endswith('\t'):
                charsToRemove = 1
            elif withSpace:
                charsToRemove = 1 if currentIndent else 0
            else:
                if self.useTabs:
                    charsToRemove = min(spacesCount(currentIndent), self.width)
                else:  # spaces
                    if currentIndent.endswith(self.text()):  # remove indent level
                        charsToRemove = self.width
                    else:  # remove all spaces
                        charsToRemove = min(spacesCount(currentIndent), self.width)

            if charsToRemove:
                cursor = cursorAtSpaceEnd(block)
                cursor.setPosition(cursor.position() - charsToRemove, QTextCursor.KeepAnchor)
                cursor.removeSelectedText()
def reset_signal_handler(cls, signal_handler):
        """Class state:

        - Overwrites `cls._signal_handler`.
        OS state:
        - Overwrites signal handlers for SIGINT, SIGQUIT, and SIGTERM.

        NB: This method calls signal.signal(), which will crash if not called from the main thread!

        :returns: The :class:`SignalHandler` that was previously registered, or None if this is
                  the first time this method was called.
        """
        assert isinstance(signal_handler, SignalHandler)
        # NB: Modify process-global state!
        for signum, handler in signal_handler.signal_handler_mapping.items():
            signal.signal(signum, handler)
            # Retry any system calls interrupted by any of the signals we just installed handlers for
            # (instead of having them raise EINTR). siginterrupt(3) says this is the default behavior on
            # Linux and OSX.
            signal.siginterrupt(signum, False)

        previous_signal_handler = cls._signal_handler
        # NB: Mutate the class variables!
        cls._signal_handler = signal_handler
        return previous_signal_handler