Generates an ETag for the given metadata. Returns undefined if no ETag could be generated.
Metadata of the representation to generate an ETag for.
Validates whether the given metadata corresponds to the given ETag.
Metadata of the resource.
ETag to compare to.
True if the comparison needs to be on representation level. False if it is on resource level and the content-type doesn't matter.
Standard implementation of ETagHandler. ETags are constructed by combining the last modified date with the content type of the representation.