def get_rml(self, rml_def, **kwargs):
        """
        returns the rml mapping output for specified mapping

        Args:
        -----
            rml_def: The name of the mapping or a dictionary definition
        """
        if isinstance(rml_def, str):
            rml_procs = self.es_defs.get("kds_esRmlProcessor", [])
            for item in rml_procs:
                if item['name'] == rml_def:
                    rml_def = item
                    break
        proc_kwargs = {rml_def['subj']: self.subject,
                       "dataset": self.dataset}
        proc_kwargs.update(rml_def['proc_kwargs'])
        return rml_def['processor'](**proc_kwargs)
returns the rml mapping output for specified mapping

        Args:
        -----
            rml_def: The name of the mapping or a dictionary definition