This function returns the name of the file for a run set
        with an extension ("txt", "xml").

def get_filename(self, runSetName, fileExtension):
        '''
        This function returns the name of the file for a run set
        with an extension ("txt", "xml").
        '''

        fileName = self.benchmark.output_base_name + ".results."

        if runSetName:
            fileName += runSetName + "."

        return fileName + fileExtension