@NotNull
    public LongStream map(@NotNull final LongUnaryOperator mapper) {
        return new LongStream(params, new LongMap(iterator, mapper));
    }
@ NotNull public LongStream map ( @ NotNull final LongUnaryOperator mapper ) { return new LongStream ( params , new LongMap ( iterator , mapper ) ) ; }
Returns an {@code LongStream} consisting of the results of applying the given
function to the elements of this stream.

<p> This is an intermediate operation.

<p>Example:
<pre>
mapper: (a) -&gt; a + 5
stream: [1, 2, 3, 4]
result: [6, 7, 8, 9]
</pre>

@param mapper  the mapper function used to apply to each element
@return the new stream
@see Stream#map(com.annimon.stream.function.Function)