code: def get_edge_values(self, feature='idx'):
          
          elist = []
          for cidx in self._coords.edges[:, 1]:
              node = self.treenode.search_nodes(idx=cidx)[0]
              elist.append(
                  (node.__getattribute__(feature) if hasattr(node, feature) else "")
                  )
          return elist
docs: Returns edge values in the order they are plotted (see .get_edges())