text: #!/usr/bin/env python
  
  """ A dummy ROS node """
  from __future__ import absolute_import
  
  import common
  import sys
  
  import rospy
  import std_msgs
  
  # TODO : implement service to check if sub
  
  
  # a callback that just echoes the message ( if it doesnt come from me )
  def topic_callback(self, data):
      pass
  
  
  if __name__ == '__main__':
      try:
          args = rospy.myargv(argv=sys.argv)
          node_name = args[1] if len(args) > 1 else 'string_pub_node'
  
          rospy.init_node(node_name)
          rospy.loginfo('String Pub node started. [' + rospy.get_name() + ']')
  
          topic_name = rospy.get_param("~topic_name", "")
          print 'Parameter {0!s} has value {1!s}'.format(rospy.resolve_name('~topic_name'), topic_name)
          if topic_name == "":
              print "{0} parameter not found".format(rospy.resolve_name('~topic_name'))
              raise common.TestArgumentNotFound
          test_message = rospy.get_param("~test_message", "")
          print 'Parameter {0!s} has value {1!s}'.format(rospy.resolve_name('~test_message'), test_message)
          if test_message == "":
              print "{0} parameter not found".format(rospy.resolve_name('~test_message'))
              raise common.TestArgumentNotFound
  
          sub = rospy.Subscriber(topic_name, std_msgs.msg.String, topic_callback)
  
          rospy.spin()
  
      except rospy.ROSInterruptException:
          pass
  