Used to resolve references ($ref or operationRef) to a JSON object. Users of the
apicurio-data-models library can provide zero or more custom implementations of
this interface in order to provide a way to resolve reference URI formats that
are not supported by default. However, internal references and external http[s]
based references are supported by default.
When providing custom reference resolvers, those custom resolvers will be used
before any default/built-in resolvers.