Here’s why I totally love python sometimes:

def _callService (self, headers, callback, errback = None, method='GET'):
    # ....
    return some_val

def _callServiceGET (*args, **kwargs):
    return args[0]._callService (*args[1:], method='GET', **kwargs)

def _callServiceHEAD (*args, **kwargs):
    return args[0]._callService (*args[1:], method='HEAD', **kwargs)

/