Why do not support meta data in service.register

[Chris8711]

I check this functions, And I want to use mata in register,but there is no entrance to use meta. pls add meta to regiseter or PR??

def register( self, name, service_id=None, address=None, port=None, tags=None, check=None, token=None, # deprecated use check parameter script=None, interval=None, ttl=None, http=None, timeout=None, enable_tag_override=False):