Program hang when channel.close()

gistfile1.py

from __future__ import with_statement
from kombu.entity import Queue, Exchange

if __name__ == '__main__':
    from kombu.connection import Connection
    from tasks import hello_task

    connection = Connection('pika://guest:guest@localhost:5672/')
    print "Got connection"
    channel=connection.channel()
    print "Got channel"
    channel.close()
    print "Closed channel"
    connection.release()
    print "Closed connection"