docs: public static String readString(ChannelBuffer buffer, Charset charset)
  	{
  		String readString = null;
  		if (null != buffer && buffer.readableBytes() > 2)
  		{
  			int length = buffer.readUnsignedShort();
  			readString = readString(buffer, length, charset);
  		}
  		return readString;
  	}