Passes a reference through only when matchShape claims it under shapes, otherwise
undefined. Accepts undefined and null, so it closes a chain of try* builders and a producer
never hands out a reference a resolver would refuse as an unsupported shape.
Under the default 'requireSupport' policy a reference carrying a version qualifier yields
undefined unless the matching shape supports a version on that component; pass 'ignore' to
match on shape alone.
Passes a reference through only when matchShape claims it under
shapes, otherwiseundefined. Acceptsundefinedandnull, so it closes a chain oftry*builders and a producer never hands out a reference a resolver would refuse as an unsupported shape.Under the default
'requireSupport'policy a reference carrying a version qualifier yieldsundefinedunless the matching shape supports a version on that component; pass'ignore'to match on shape alone.