code: public String replace(String source, String pattern,
                            String replacement, int fromIndex) {
          return StringReplacer.replace(source, pattern, replacement, fromIndex);
      }
docs: Replaces all exact matches of the given pattern in the source string
  with the provided replacement, starting from the given index.
  
  @param source the source string
  @param pattern the simple string pattern to search for
  @param replacement the string to use for replacing matched patterns.
  @param fromIndex index to start the replace
  
  @return the string with any replacements applied.