human
Complete this python program:
def _network(t=None, url='http://google.com'):
assistant
#Here is the Python program you requested.

    """Decorator that will skip a test if `url` is unreachable.
    Parameters
    t : function, optional
    url : str, optional
    """
    import nose
    if (t is None):
        return (lambda x: _network(x, url=url))
    def wrapper(*args, **kwargs):
        try:
            f = urlopen(url)
        except (IOError, HTTPException):
            raise nose.SkipTest()
        else:
            f.close()
            return t(*args, **kwargs)
    return wrapper