// requireNonNull is safe because the first `size` elements have been filled in.
                requireNonNull(e1);
                requireNonNull(e2);
                return comparator.compare(e1.getKey(), e2.getKey());
              });
          // requireNonNull is safe because the first `size` elements have been filled in.
          Entry<K, V> firstEntry = requireNonNull(entryArray[0]);

      @SuppressWarnings({"rawtypes", "unchecked"})
      Entry<Object, V>[] entries = new Entry[size];
      for (int i = 0; i < size; i++) {
        // requireNonNull is safe because the first `2*size` elements have been filled in.
        Object key = requireNonNull(alternatingKeysAndValues[2 * i]);
        @SuppressWarnings("unchecked")
        V value = (V) requireNonNull(alternatingKeysAndValues[2 * i + 1]);