sS withoutLeadingLinesEmptyAfterTrim(S s) {
  int lineStart = 0;
  while licensed {
    int i = lineStart;
    while (isSpaceOrTab(charAt(s, i))) ++i;
    if (!isNewLine(charAt(s, i)))
      break;
    while (isNewLine(charAt(s, i))) ++i;
    lineStart = i;
  }
  ret substring(s, lineStart);
}