def METHOD_NAME(varname):
   'returns the TaggingVariableName of a MVA Name'
   match = var_match(varname)
   name = match.group('name')
   if name not in training_vars:
      raise ValueError(
         'Variable name {0}, matched to name {1}, '
         'is not among the known trainig variables.'.format(
            varname, name)
         )
   return name