Republish a message already existed with Header

edit

Hey guys, I 'm trying to republish a bumper's message with Header for message_filters (I'm using rospy) but doesn't work.Help me this is my code:

import rospy
from kobuki_msgs.msg import BumperEvent
from bumpertest.msg import bumpermsg
import std_msgs.msg

def main(): 
    rospy.init_node('bumpertest')
    h = std_msgs.msg.Header()
    h.stamp = rospy.Time.now()
    pub = rospy.Publisher('bumpermio',bumpermsg, queue_size=10)
    bumperob= bumper(h,pub)
    rospy.Subscriber("/mobile_base/events/bumper",BumperEvent, bumperob.callback)   
    rospy.spin()