builder

Returns a builder for a handler with the specified default callback. The default handler will receive all key/value pairs from the metadata individually, which can result in repeated keys being seen more than once.

A default handler is required because no handler can know the complete set of keys which might be available and it is very undesirable to drop unknown keys. If default repeated values should be handled together, setDefaultRepeatedHandler should be called as well.

Unknown keys/values can only be handled in a generic fashion unless a given key is matched to a known constant. However the entire point of this map-based handler is to avoid any need to do explicit matching, so the default handler should not need to know the value type.

Parameters