code: def to_dict(self):
          
          return {
              'model_type': 'segmented_regression',
              'name': self.name,
              'segmentation_col': self.segmentation_col,
              'fit_filters': self.fit_filters,
              'predict_filters': self.predict_filters,
              'min_segment_size': self.min_segment_size,
              'default_config': {
                  'model_expression': self.default_model_expr,
                  'ytransform': YTRANSFORM_MAPPING[self.default_ytransform]
              },
              'fitted': self.fitted,
              'models': {
                  yamlio.to_scalar_safe(name):
                      self._process_model_dict(m.to_dict())
                  for name, m in self._group.models.items()}
          }
docs: Returns a dict representation of this instance suitable for
          conversion to YAML.