private static List<FieldInfo> fieldInfos() {
        return ImmutableList.of(
                FieldInfo.builder("query", STRING).requirement(FieldRequirement.REQUIRED).build(),
                FieldInfo.builder("operationName", STRING).requirement(FieldRequirement.OPTIONAL).build(),
                FieldInfo.builder("variables", MAP).requirement(FieldRequirement.OPTIONAL).build(),
                FieldInfo.builder("extensions", MAP).requirement(FieldRequirement.OPTIONAL).build()
        );
    }
A {@link DocServicePlugin} implementation that supports the {@link AbstractGraphqlService}.
graphql/src/main/java/com/linecorp/armeria/internal/server/graphql/GraphqlDocServicePlugin.java