code: function __deserializeIntVar(buffer, start, options) {
  	const dataBuff = new Uint8Array(buffer);
  	if ( dataBuff[start] > 127 ) {
  		throw new Error( "Cannot support IntVar whose size is greater than 127 bytes" );
  	}
  	
  	
  	
  	let index = 0, data_size = dataBuff[start], end = start + 1;
  	const result_buffer = new Uint8Array(data_size);
  	while( data_size-- > 0 ) {
  		result_buffer[index] = dataBuff[end];
  		index++; end++;
  	}
  
  
  	let data = new IntVar(result_buffer);
  	return { anchor: end, value: data };
  }
docs: Deserialize IntVar data
  @param {ArrayBuffer} buffer
  @param {number} start - byteOffset
  @param {DeserializeOptions} options
  @returns {{anchor: number, value: IntVar}} anchor: byteOffset
  @private