code: def set_type(self, sequence_type):
          '''Set the type of a Sequence if it has not been set.'''
          if not(self.sequence_type):
              for id, r in self.sequence.iteritems():
                  assert(r.residue_type == None)
                  r.residue_type = sequence_type
              self.sequence_type = sequence_typf set_type(self, sequence_type):
          '''Set the type of a Sequence if it has not been set.'''
          if not(self.sequence_type):
              for id, r in self.sequence.iteritems():
                  assert(r.residue_type == None)
                  r.residue_type = sequence_type
              self.sequence_type = sequence_type
docs: Set the type of a Sequence if it has not been set.