Fix a small typo in GuavaOptionalSubject
RELNOTES=n/a
@@ -21,7 +21,7 @@ import javax.annotation.Nullable;
/**
* Propositions for Guava {@link Optional} subjects.
*
- * <p>If you are looking a {@code java.util.Optional} subject, please read
+ * <p>If you are looking for a {@code java.util.Optional} subject, please read
* <a href="http://google.github.io/truth/faq#java8">faq#java8</a>
*
* @author Christian Gruber
