/guava/android/guava/src/com/google/common/collect/MoreCollectors.java
if ( o == null) {
if ( element == null ) {
extras.add(o); } else { throw multiples(true); } } ToOptionalState combine(ToOptionalState other) { <extra_id_0> return other; } else if (other.element == null) { return this; } else { if (extras.isEmpty()) { extras = new ArrayList<>();