Retrieve the siblings of a textual node

        :param textId: CtsTextMetadata Identifier
        :type textId: str
        :param level: Depth for retrieval
        :type level: int
        :param subreference: CapitainsCtsPassage Reference
        :type subreference: str
        :param include_descendants:
        :param additional_parameters:
        :return: List of references
        :rtype: [str]

        ..toDo :: This starts to be a bloated function....

def getReffs(
            self,
            textId: str,
            level: int=1,
            subreference: Union[str, BaseReference]=None,
            include_descendants: bool=False,
            additional_parameters: Optional[Dict[str, Any]]=None
    ) -> BaseReferenceSet:
        """ Retrieve the siblings of a textual node

        :param textId: CtsTextMetadata Identifier
        :type textId: str
        :param level: Depth for retrieval
        :type level: int
        :param subreference: CapitainsCtsPassage Reference
        :type subreference: str
        :param include_descendants:
        :param additional_parameters:
        :return: List of references
        :rtype: [str]

        ..toDo :: This starts to be a bloated function....
        """
        raise NotImplementedError()