'checkout from url to local wcpath.'

def checkout(self, url=None, rev=None):

    args = []
    if (url is None):
        url = self.url
    if ((rev is None) or (rev == (-1))):
        if ((py.std.sys.platform != 'win32') and (_getsvnversion() == '1.3')):
            url += '@HEAD'
    elif (_getsvnversion() == '1.3'):
        url += ('@%d' % rev)
    else:
        args.append(('-r' + str(rev)))
    args.append(url)
    self._authsvn('co', args)
