code: @SuppressWarnings("unchecked")
      public T headerValidator(String ... validatorNames) {
          Assert.notNull(applicationContext, "Citrus application context is not initialized!");
  
          for (String validatorName : validatorNames) {
              headerValidationContext.addHeaderValidator(applicationContext.getBean(validatorName, HeaderValidator.class));
          }
  
          return self;
      }
docs: Sets explicit header validators by name.
  @param validatorNames
  @return