Better CpsBodySubContext.toString

Author: jglick

plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/CpsBodySubContext.java

@@ -57,6 +57,10 @@ public int hashCode() {
     // Delegation to 'base' from here
 //======================================
 
+    @Override
+    public String toString() {
+        return "CpsBodySubContext[" + base + ":" + node.getId()+ "]";
+    }
 
     @Override
     public void onFailure(Throwable t) {