def get_sample_field_schema(self):
        """Returns a dictionary describing the field schema of the samples
        loaded by this importer.

        Returns:
            a dict mapping field names to :class:`fiftyone.core.fields.Field`
            instances or ``str(field)`` representations of them
        """
        if not self.has_sample_field_schema:
            raise ValueError(
                "This '%s' does not provide a sample field schema"
                % etau.get_class_name(self)
            )

        raise NotImplementedError(
            "subclass must implement get_sample_field_schema()"
        )
Returns a dictionary describing the field schema of the samples
        loaded by this importer.

        Returns:
            a dict mapping field names to :class:`fiftyone.core.fields.Field`
            instances or ``str(field)`` representations of them
        
fiftyone/utils/data/importers.py