code: def _generate_struct_class_repr(self, data_type):
          
          self.emit('def __repr__(self):')
          with self.indent():
              if data_type.all_fields:
                  constructor_kwargs_fmt = ', '.join(
                      '{}={{!r}}'.format(fmt_var(f.name, True))
                      for f in data_type.all_fields)
                  self.emit("return '{}({})'.format(".format(
                      class_name_for_data_type(data_type),
                      constructor_kwargs_fmt,
                  ))
                  with self.indent():
                      for f in data_type.all_fields:
                          self.emit("self._{}_value,".format(fmt_var(f.name)))
                  self.emit(")")
              else:
                  self.emit("return '%s()'" %
                            class_name_for_data_type(data_type))
          self.emit()
docs: Generates something like:
  
              def __repr__(self):
                  return 'Employee(first_name={!r}, last_name={!r}, age={!r})'.format(
                      self._first_name_value,
                      self._last_name_value,
                      self._age_value,
                  )