code: public static LongStreamEx of(java.nio.LongBuffer buf) {
          return IntStreamEx.range(buf.position(), buf.limit()).mapToLong(buf::get);
      }
docs: Returns a sequential ordered {@code LongStreamEx} whose elements are the
  values in the supplied {@link java.nio.LongBuffer}.
  
  <p>
  The resulting stream covers only a portion of {@code LongBuffer} content
  which starts with {@linkplain Buffer#position() position} (inclusive) and
  ends with {@linkplain Buffer#limit() limit} (exclusive). Changes in
  position and limit after the stream creation don't affect the stream.
  
  <p>
  The resulting stream does not change the internal {@code LongBuffer}
  state.
  
  @param buf the {@code LongBuffer} to create a stream from
  @return the new stream
  @since 0.6.2