[BioC] the edgeNames( ), and the label for the edge in a node-edge plot created in Graphviz

[Yilin Liu]

every time you construct a graph object, you can use edgeNames() function to return the edge names in the graph, e.g. if node "A" is connected with node "B", then the edge name is returned as "A~B".
I want to know whether i can set the edge name by myself, e.g. I'd like to call it "L1".
 
Another question is when I convert a graph into a .gxl file in R, i can plot it in Graphviz. Is it possible to include labels for all the edges and get edge labels shown in the graph the sames as the node labels.