<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def clearSyntax(self):
 """Clear syntax. Disables syntax highlighting This method might take long time, if document is big. Don't call it if you don't have to (i.e. in destructor) """

        if self._highlighter is not None:
            self._highlighter.terminate()
            self._highlighter = None
            self.languageChanged.emit(None)