label_scheme
Whether to treat a node whose name has the form 
|edgelabel|* as a special node representing an edge label.
type: int, default: 0, minimum: 0
- The default, 
label_scheme=0, produces no effect. - If 
label_scheme=1,sfdpuses a penalty-based method to make that kind of node close to the center of its neighbor. - With 
label_scheme=2,sfdpuses a penalty-based method to make that kind of node close to the old center of its neighbor. - Finally, 
label_scheme=3invokes a two-step process of overlap removal and straightening. 
- Graphs
 
Note: sfdp only.