def get_trace_names(config_filename):
   """
   Returns a list with a single tuple in it. 
   The tuple is of the traces that are used in the config file.
   """
   traces = []
   f = open(config_filename, 'U')
   for line in f:
      if line.strip() != '':
         if 'trace' in line:
            trace_name = line.strip().split(' ')[1]
            traces.append(trace_name)
   return [tuple(traces)]