def _field_data(self, block, name):
        """Return the field data for the field `name` on the :class:`~xblock.core.XBlock` `block`"""
        scope = block.fields[name].scope

        if scope not in self._scope_mappings:
            raise InvalidScopeError(scope)

        return self._scope_mappings[scope]
Return the field data for the field `name` on the :class:`~xblock.core.XBlock` `block`