@staticmethod
def url(path, params={}):
    result = Exchange.implode_params(path, params)
    query = Exchange.omit(params, Exchange.extract_params(path))
    if query:
        result += ('?' + _urlencode.urlencode(query))
    return result
@staticmethod
def url(path, params={}):
    result = Exchange.implode_params(path, params)
    query = Exchange.omit(params, Exchange.extract_params(path))
    if query:
        result += ('?' + _urlencode.urlencode(query))
    return result