def resolve_content_type(type_resolvers, request):
    # type: (Iterable[Callable[[Any], str]], Any) -> Optional[str]
    """
    Resolve content types from a request.
    """
    for resolver in type_resolvers:
        content_type = parse_content_type(resolver(request))
        if content_type:
            return content_type
Resolve content types from a request.