code: public static int ordinalIndexOf(final String str, final String substr, final int ordinal) {
          return ordinalIndexOf(str, substr, ordinal, false);
      }
docs: <p>
  Finds the n-th index within a String, handling {@code null}.
  </p>
  
  @param str
  @param substr
  @param ordinal
  the n-th {@code searchStr} to find
  @return the n-th index of the search String, {@code -1} (
  {@code N.INDEX_NOT_FOUND}) if no match or {@code null} or empty
  string input