code: function convertUint8ArraysToArrays(sources) {
    var targets = [];
    for (var n = 0; n < sources.length; n++) {
      var source = sources[n];
      var target = new Array(source.length);
      for (var i = 0; i < source.length; i++) {
        target[i] = source[i];
      }
      targets.push(target);
    }
    return targets;
  }
docs: Converts a list of Uint8Arrays to regular arrays.
  @param {!Array.<!Uint8Array>} sources Source arrays.
  @return {!Array.<!Array.<number>>} Target arrays.