guava/src/com/google/common/reflect/TypeToken.java
public final TypeToken<T> wrap() {
    if (isPrimitive()) {
      @SuppressWarnings("unchecked") // this is a primitive class
      Class<T> type = (Class<T>) runtimeType;
      return of(Primitives.wrap(type));
    }
    return this;
  }
public final TypeToken<T> wrap() {
    if (isPrimitive()) {
      @SuppressWarnings("unchecked") // this is a primitive class
      Class<T> type = (Class<T>) runtimeType;
      return of(Primitives.wrap(type));
    }
    return this;
  }
Returns the corresponding wrapper type if this is a primitive type; otherwise returns {@code
this} itself. Idempotent.

@since 15.0