def all_field_map(self) -> Dict[str, Field]:
        """
        A map from field name, lexical name and filter name to the Field object.
        """
        return self._cache_or_get('all_field_map',
                                  lambda: {
                                      **{field.name: field for field in self.fields},
                                      **{field.lexical_field_name: field for field in self.fields if
                                         field.lexical_field_name is not None},
                                      **{field.filter_field_name: field for field in self.fields if
                                         field.filter_field_name is not None}
                                  }
                                  )

        A map from field name, lexical name and filter name to the Field object.
        
src/marqo/core/models/marqo_index.py