code: public static void validate(final String string, final List<String> params) {
          final List<String> vars = findVars(string);
          for (String param : params) {
              Preconditions.checkState(vars.contains(param),
                      "Variable '%s' not found in target string '%s'", param, string);
          }
          vars.removeAll(params);
          Preconditions.checkState(vars.isEmpty(),
                  "No parameter binding defined for variables '%s' from string '%s'",
                  Joiner.on(',').join(vars), string);
      }
docs: Validate string variables and declared values for correctness.
  
  @param string template string
  @param params provided param names