Cannot find out arm_control_msgs

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I am using ROS groovy on Ubuntu precise. Recently I am trying to convert a code which works on Diamondback to Groovy. But the problem is that some files used to be available in Diamondback now does not exist in Groovy. For example, when I look at file "regression_test_pose_goal_floorobj.cpp" located at "/opt/ros/groovy/stacks/arm_navigation/move_arm/test/regression_test_pose_goal_floorobj.cpp ", it has "#include <arm_control_msgs/TrajectoryStart.h>" but I cannot find TrajectoryStart.h, even worse, I cannot find out any folder or file named arm_control_msgs in the root directory of groovy. When I search for the dos of packages of Diamondback and Electric, I cannot find out anything similar to arm_control_msgs. So :

1. anyone can help me find out where "arm_control_msgs" is?
2. Or tell me what kind of changes have been made to this file(or package?) in Groovy so that I cannot include the new version of header file in my program or make some changes to my program.