'Dump the contents, empty or not, to the log.'

def Log(self, prefix='URL', level=3):

    out = (prefix + ':')
    for attribute in self.__slots__:
        value = getattr(self, attribute)
        if (not value):
            value = ''
        out = (out + ('        %s=[%s]' % (attribute, value)))
    output.Log(('%s' % encoder.NarrowText(out, None)), level)
