[prone] Apply UnusedMethod

Author: Vincent Potucek

gradle/error-prone.gradle

@@ -53,7 +53,7 @@ tasks.withType(JavaCompile).configureEach {
 		// up2date checking (caching) must consider file changes, as file is currently corrupt!
 		// fix SelfTest.java:L22 ForbidGradleInternal(import org.gradle.api.internal.project.ProjectInternal;)
 		errorproneArgs.add('-XepExcludedPaths:.*/SelfTest.java')
-		// bug @MethodSource
+		// bug https://github.com/google/error-prone/issues/5289
 		errorproneArgs.add('-XepExcludedPaths:.*/EclipseJdtFormatterStepTest.java')
 		errorproneArgs.add('-XepExcludedPaths:.*/JvmTest.java')
 		if (!getenv().containsKey('CI') && getenv('IN_PLACE')?.toBoolean()) {