code: private IEdge removeEdgeOnVertexDelete(UUID edgeId) throws BitsyException {
          // This is called from remove on adjMap, which means that the edge was added in this Tx
          BitsyEdge edge = changedEdges.remove(edgeId);
          
          // Only an edge that is present in this Tx can be removed by the IEdgeRemover
          assert (edge != null);
          
          return edge;
      }
docs: This method is called to remove an edge through the IEdgeRemover