Mark OptionsParser.Builder#optionsClasses() as @SafeVarargs.

RELNOTES: None.
PiperOrigin-RevId: 300397875
diff --git a/src/main/java/com/google/devtools/common/options/OptionsParser.java b/src/main/java/com/google/devtools/common/options/OptionsParser.java
index 8b6e673..98fb74e 100644
--- a/src/main/java/com/google/devtools/common/options/OptionsParser.java
+++ b/src/main/java/com/google/devtools/common/options/OptionsParser.java
@@ -160,7 +160,8 @@
     /**
      * Sets the {@link OptionsData} used by this parser, based on the given {@code optionsClasses}.
      */
-    public Builder optionsClasses(Class<? extends OptionsBase>... optionsClasses) {
+    @SafeVarargs
+    public final Builder optionsClasses(Class<? extends OptionsBase>... optionsClasses) {
       return this.optionsData(
           (OpaqueOptionsData) getOptionsDataInternal(ImmutableList.copyOf(optionsClasses)));
     }