code: @Override
      public boolean offer(final E e)
      {
          // Objects.requireNonNull(e);
          if (null == e)
          {
              throw new NullPointerException();
          }
          // local load of field to avoid repeated loads after volatile reads
          final E[] buffer = producerBuffer;
          final long index = lpProducerIndex();
          final long mask = producerMask;
          final long offset = calcElementOffset(index, mask);
          // expected hot path
          if (index < producerBufferLimit)
          {
              writeToQueue(buffer, e, index, offset);
              return true;
          }
          return offerColdPath(buffer, mask, index, offset, e, null);
      }
docs: {@inheritDoc}
  <p>
  This implementation is correct for single producer thread use only.