public static int hashCode(@Nullable Object o) {
        return o != null ? o.hashCode() : 0;
    }
Returns the hash code of a non-{@code null} argument and 0 for a {@code null} argument.

@param o an object
@return the hash code of a non-{@code null} argument and 0 for a {@code null} argument
@see Object#hashCode
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/compat/ObjectsCompat.java