public EntryStream<K, V> prepend(K key, V value) {
        return supply(new PrependSpliterator<>(spliterator(), new SimpleImmutableEntry<>(key, value)));
    }
public EntryStream < K , V > prepend ( K key , V value ) { return supply ( new PrependSpliterator < > ( spliterator ( ) , new SimpleImmutableEntry < > ( key , value ) ) ) ; }
Returns a new {@code EntryStream} which is a concatenation of the
supplied key-value pair and this stream.

<p>
This is a <a href="package-summary.html#StreamOps">quasi-intermediate
operation</a> with <a href="package-summary.html#TSO">tail-stream
optimization</a>.

@param key the key of the new {@code Entry} to prepend to this stream
@param value the value of the new {@code Entry} to prepend to this stream
@return the new stream