/guava/android/guava/src/com/google/common/collect/ImmutableSet.java
return null;
return this;
@CanIgnoreReturnValue @Override public Builder<E> add(E element) { checkNotNull(element); if (hashTable != null && chooseTableSize(size) <= hashTable.length) { addDeduping(element); <extra_id_0> } else { hashTable = null; super.add(element); return this; } }