docs: public final void setDelegate(Object delegate) {
  		this.classifier = null;
  		this.invoker = MethodInvokerUtils.getMethodInvokerByAnnotation(
  				org.springframework.classify.annotation.Classifier.class, delegate);
  		if (this.invoker == null) {
  			this.invoker = MethodInvokerUtils
  					.<C, T>getMethodInvokerForSingleArgument(delegate);
  		}
  		Assert.state(this.invoker != null,
  				"No single argument public method with or without "
  						+ "@Classifier was found in delegate of type "
  						+ delegate.getClass());
  	}