Check shortcuts for conflicts.

def check_conflicts(self):
        """Check shortcuts for conflicts."""
        conflicts = []
        if len(self._qsequences) == 0:
            return conflicts

        new_qsequence = self.new_qsequence
        for shortcut in self.shortcuts:
            shortcut_qsequence = QKeySequence.fromString(str(shortcut.key))
            if shortcut_qsequence.isEmpty():
                continue
            if (shortcut.context, shortcut.name) == (self.context, self.name):
                continue
            if shortcut.context in [self.context, '_'] or self.context == '_':
                if (shortcut_qsequence.matches(new_qsequence) or
                        new_qsequence.matches(shortcut_qsequence)):
                    conflicts.append(shortcut)
        return conflicts