1 files changed, 9 insertions, 0 deletions
diff --git a/graph/src/labelled/binary.rs b/graph/src/labelled/binary.rs
index 5120522..862f25b 100644
--- a/graph/src/labelled/binary.rs
+++ b/graph/src/labelled/binary.rs
@@ -420,6 +420,11 @@ impl<T: GraphLabel> LabelGraph<T> for PLGraph<T> {
         Self: 'a,
         T: 'a;
 
+    type TupleIter<'a> = std::iter::Empty<(T, usize)>
+    where
+        Self: 'a,
+        T: 'a;
+
     #[inline]
     fn query_label(&self, label: T) -> Option<usize> {
         self.label_index_map.get(&label).copied()
@@ -446,6 +451,10 @@ impl<T: GraphLabel> LabelGraph<T> for PLGraph<T> {
         unimplemented!("Edges have no labels")
     }
 
+    fn tuples_of(&self, _node_id: usize) -> Result<Self::TupleIter<'_>, Error> {
+        unimplemented!("Edges have no labels")
+    }
+
     fn labels_of(&self, _node_id: usize) -> Result<Self::LabelIter<'_>, Error> {
         unimplemented!("Edges have no labels")
     }