code: def _dump_field(self, fd):
          
          v = {}
          v['label'] = Pbd.LABELS[fd.label]
          v['type'] = fd.type_name if len(fd.type_name) > 0 else Pbd.TYPES[fd.type]
          v['name'] = fd.name
          v['number'] = fd.number
          v['default'] = '[default = {}]'.format(fd.default_value) if len(fd.default_value) > 0 else ''
          
          f = '{label} {type} {name} = {number} {default};'.format(**v)
          f = ' '.join(f.split())
          self._print(f)
          
          if len(fd.type_name) > 0:
              self.uses.append(fd.type_name)
docs: Dump single field.