code: public SettingsPack sendBufferWatermark(int value) {
          sp.set_int(settings_pack.int_types.send_buffer_watermark.swigValue(), value);
          return this;
      }
docs: Sets the upper limit of the send buffer low-watermark.
  <p>
  if the send buffer has fewer bytes than this, we'll read another 16kB
  block onto it. If set too small, upload rate capacity will suffer. If
  set too high, memory will be wasted. The actual watermark may be lower
  than this in case the upload rate is low, this is the upper limit.
  
  @param value