The shared answer for a vertex without edges. Use it instead of a fresh [] fallback, the lookups sit in
traversal loops where a miss is the common case.
You rarely need it by hand: DataflowGraph#edgesFrom|edgesFrom() and
DataflowGraph#edgesTo|edgesTo() already answer with it rather than with undefined.
The shared answer for a vertex without edges. Use it instead of a fresh
[]fallback, the lookups sit in traversal loops where a miss is the common case.You rarely need it by hand: DataflowGraph#edgesFrom|edgesFrom() and DataflowGraph#edgesTo|edgesTo() already answer with it rather than with
undefined.