code: private Object readResolve() throws ObjectStreamException {
          if (triggerScript != null && secureTriggerScript == null) {
              this.secureTriggerScript = new SecureGroovyScript(triggerScript, false, null);
              this.secureTriggerScript.configuring(ApprovalContext.create());
              triggerScript = null;
          }
          return this;
      }
docs: Called when object has been deserialized from a stream.
  
  @return {@code this}, or a replacement for {@code this}.
  @throws ObjectStreamException if the object cannot be restored.
  @see <a href="http://download.oracle.com/javase/1.3/docs/guide/serialization/spec/input.doc6.html">The Java Object Serialization Specification</a>