code: @Override
      protected void doInitialize() throws ComponentInitializationException {
          log.debug("Initialized {}", this.getClass().getSimpleName());
          if (getMessageContext() == null) {
              throw new ComponentInitializationException("Message context cannot be null");
          }
          if (getVelocityEngine() == null) {
              throw new ComponentInitializationException("VelocityEngine must be supplied");
          }
          if (getVelocityTemplateId() == null) {
              throw new ComponentInitializationException("Velocity template id must be supplied");
          }
      }
docs: Check component attributes. Copy/Paste parents initialization (no super.doInitialize) except for
  AbstractHttpServletResponseMessageEncoder since HttpServletResponse is always null.
  
  @throws ComponentInitializationException if initialization fails