Returns the line number for the documents debug line.
        
        :param      lineno | <int>

def setCurrentDebugLine( self, lineno ):
        """
        Returns the line number for the documents debug line.
        
        :param      lineno | <int>
        """
        self.markerDeleteAll(self._currentDebugMarker)
        self.markerAdd(lineno, self._currentDebugMarker)
        self.setCurrentLine(lineno)