return getSubtypeFromLowerBounds(subclass, ((WildcardType) runtimeType).getLowerBounds());
    }
    // unwrap array type if necessary
    if (isArray()) {
      return getArraySubtype(subclass);
    }
    // At this point, it's either a raw class or parameterized type.
    checkArgument(
        getRawType().isAssignableFrom(subclass), "%s isn't a subclass of %s", subclass, this);