static mergeBuffers(leftBuffer, rightBuffer) {
    const tmpArray = new Uint8Array(
      leftBuffer.byteLength + rightBuffer.byteLength
    );
    tmpArray.set(new Uint8Array(leftBuffer), 0);
    tmpArray.set(new Uint8Array(rightBuffer), leftBuffer.byteLength);
    return tmpArray.buffer;
  }
Concatenates two ArrayBuffers
@param {ArrayBuffer} leftBuffer
@param {ArrayBuffer} rightBuffer
@returns {ArrayBuffer}