This method will be called by the consumer such as a Graph
factory and
must return the weight of the edge the edge stream cursor has been moved to.
(weightedAdapter: StringAdd).self
(weightedAdapter: StringFormat).self
(weightedAdapter: ArrowAssoc[WeightedAdapter]).x
(Since version 2.10.0) Use leftOfArrow
instead
(weightedAdapter: Ensuring[WeightedAdapter]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
Adapter submitting the weight component of an edge.