It would be better if we had an explicit method to identify when code is run...

It would be better if we had an explicit method to identify when code is run in a thread on the master vs in a thread on a slave

 - because forcing the slave to load the Jenkins class into its classloader is probably not a good plan

core/src/main/java/hudson/slaves/SlaveComputer.java

@@ -835,7 +835,7 @@ public class SlaveComputer extends Computer {
      * @since 1.362
      */
     public static VirtualChannel getChannelToMaster() {
-        if (Jenkins.getInstanceOrNull()!=null)
+        if (Jenkins.getInstanceOrNull()!=null) // check if calling thread is on master or on slave
             return FilePath.localChannel;
 
         // if this method is called from within the slave computation thread, this should work