Rename method for adding custom argument resolvers

See gh-603

Author: rstoyanchev

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurer.java

@@ -153,15 +153,15 @@ public void addFormatterRegistrar(FormatterRegistrar registrar) {
 	}
 
 	/**
-	 * Add {@link HandlerMethodArgumentResolver}'s for custom controller method
+	 * Add a {@link HandlerMethodArgumentResolver} for custom controller method
 	 * arguments. Such custom resolvers are ordered after built-in resolvers
 	 * except for {@link SourceMethodArgumentResolver}, which is always last.
 	 *
-	 * @param resolvers the resolvers to add.
+	 * @param resolver the resolver to add.
 	 * @since 1.2
 	 */
-	public void setCustomArgumentResolver(List<HandlerMethodArgumentResolver> resolvers) {
-		this.customArgumentResolvers.addAll(resolvers);
+	public void addCustomArgumentResolver(HandlerMethodArgumentResolver resolver) {
+		this.customArgumentResolvers.add(resolver);
 	}
 
 	HandlerMethodArgumentResolverComposite getArgumentResolvers() {

spring-graphql/src/test/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurerTests.java

@@ -15,7 +15,6 @@
  */
 package org.springframework.graphql.data.method.annotation.support;
 
-import java.util.Collections;
 import java.util.List;
 
 import org.junit.jupiter.api.Test;
@@ -41,8 +40,8 @@ void customArgumentResolvers() {
 		HandlerMethodArgumentResolver customResolver2 = mock(HandlerMethodArgumentResolver.class);
 
 		AnnotatedControllerConfigurer configurer = new AnnotatedControllerConfigurer();
-		configurer.setCustomArgumentResolver(Collections.singletonList(customResolver1));
-		configurer.setCustomArgumentResolver(Collections.singletonList(customResolver2));
+		configurer.addCustomArgumentResolver(customResolver1);
+		configurer.addCustomArgumentResolver(customResolver2);
 		configurer.setApplicationContext(new StaticApplicationContext());
 		configurer.afterPropertiesSet();