roswtf: unconnected subscription warning?

edit

In particular the unconnected node subscriptions?

$ roswtf
Loaded plugin tf.tfwtf
No package or stack in the current directory
================================================================================
Static checks summary:

No errors or warnings
================================================================================
Beginning tests of your ROS graph. These may take a while...
analyzing graph...
... done analyzing graph
running graph rules...
... done running graph rules
running tf checks, this will take a second...
... tf checks complete

Online checks summary:

Found 1 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING The following node subscriptions are unconnected:
 * /ekf_localization:
   * /set_pose
 * /joy_node:
   * /joy/set_feedback
 * /rosserial_lino:
   * /pid