docs: public Packer ensureCapacity(int minCapacity) {
  		if (minCapacity <= buf.length)
  			return this;
  		switch (autoExtendPolicy) {
  			case NONE:
  				return this;
  			case MINIMAL:
  				break;
  			case AUTO:
  				minCapacity = roundAuto(minCapacity);
  				break;
  			case ROUND8:
  				minCapacity = round(minCapacity, 8);
  				break;
  			case ROUND512:
  				minCapacity = round(minCapacity, 512);
  				break;
  			case ROUND4096:
  				minCapacity = round(minCapacity, 4096);
  				break;
  		}
  		final byte[] newbuf = new byte[minCapacity];
  		System.arraycopy(buf, 0, newbuf, 0, Math.min(buf.length, newbuf.length));
  		buf = newbuf;
  		bufLimit = buf.length;
  		return this;
  	}