dgr_graph
using node ID values. If nodes have IDs that are
monotonically increasing integer values, then numeric ranges can
be used for the selection.select_edges_by_node_id(graph, nodes, set_op = "union")
dgr_graph
that is created
using create_graph
.union
(the default), as an
intersection
, or, as a difference
on the previous selection,
if it exists.dgr_graph
.