/guava/android/guava/src/com/google/common/collect/ImmutableCollection.java
getReadyToExpandTo( n + size) ;
getReadyToExpandTo ( size + n ) ;
public Builder<E> add(E... elements) { addAll(elements, elements.length); return this; } final void addAll(@Nullable Object[] elements, int n) { checkElementsNotNull(elements, n); <extra_id_0> System.arraycopy(elements, 0, contents, size, n); size += n; } @CanIgnoreReturnValue @Override public Builder<E> addAll(Iterable<? extends E> elements) {