def by_relation_id(self,relation_id: str) -> RelationItemRequestBuilder:
        """
        Provides operations to manage the relations property of the microsoft.graph.termStore.term entity.
        param relation_id: The unique identifier of relation
        Returns: RelationItemRequestBuilder
        """
        if relation_id is None:
            raise TypeError("relation_id cannot be null.")
        from .item.relation_item_request_builder import RelationItemRequestBuilder

        url_tpl_params = get_path_parameters(self.path_parameters)
        url_tpl_params["relation%2Did"] = relation_id
        return RelationItemRequestBuilder(self.request_adapter, url_tpl_params)

        Provides operations to manage the relations property of the microsoft.graph.termStore.term entity.
        param relation_id: The unique identifier of relation
        Returns: RelationItemRequestBuilder
        
msgraph/generated/sites/item/term_stores/item/sets/item/terms/item/children/item/relations/relations_request_builder.py