docs: function glFunctionArgsToString(functionName, args) {
    // apparently we can't do args.join(",");
    var argStr = "";
    for (var ii = 0; ii < args.length; ++ii) {
      argStr += ((ii == 0) ? '' : ', ') +
          glFunctionArgToString(functionName, ii, args[ii]);
    }
    return argStr;
  }