A provider interface provides a "toSomething(?)" method which
converts a given instance into something else.
Returns the HTTP media type: It consists of the Media-Top-Level-Type
and the Media-Subtype as well as some (optional) suffixed parameters
all being concatenated in an HTTP valid manner, such as:
The HTTP header Media-Type as of the IANA specification.
EXC - Thrown in case providing the type as String