code: public static String replace(String input, String find, String repl, boolean firstOnly) {
  	return replace(input, find, repl, firstOnly, false);
      }
docs: maintains the legacy signature of this method where matches are CaSe sensitive (sets the default
  of ignoreCase to false).
  
  @param input - the string input to work on
  @param find - the substring to find
  @param repl - the substring to replace the matches with
  @param firstOnly - if true then only the first occurrence of {@code find} will be replaced
  @return - calls replace( input, find, repl, firstOnly, false )