text: # Copyright 2016 Open Source Robotics Foundation, Inc.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from agv_service.srv import AgvDataServicev1
  
  import rclpy
  import sys
  
  def main(args=None):
      rclpy.init(args=args)
  
      node = rclpy.create_node('agv_data_client')
  
      cli = node.create_client(AgvDataServicev1, '/agv_data_service')
  
      req = AgvDataServicev1.Request()
      req.istek = sys.argv[1]
      while not cli.wait_for_service(timeout_sec=1.0):
          node.get_logger().info('service not available, waiting again...')
  
      future = cli.call_async(req)
      while rclpy.ok():
          rclpy.spin_once(node)
          if future.done():
              if future.result() is not None:
                  node.get_logger().info(
                      'Result of add_two_ints: for %s + %s' %
                      (req.istek, future.result().cevap))
              else:
                  node.get_logger().info('Service call failed %r' % (future.exception(),))
              break
  
      node.destroy_node()
      rclpy.shutdown()
  
  
  if __name__ == '__main__':
      main()
  