docs: def assign_parser(self, name):
          '''
          Restricts parsing
          **name** is a name of the parser class
          NB: this is the PUBLIC method
          @procedure
          '''
          for n, p in list(self.Parsers.items()):
              if n != name:
                  del self.Parsers[n]
          if len(self.Parsers) != 1:
              raise RuntimeError('Parser cannot be assigned!')