code: static boolean resemblesPragma(String rule, int pos, int limit) {
          // Must start with /use\s/i
          return Utility.parsePattern(rule, pos, limit, "use ", null) >= 0;
      }
docs: Return true if the given rule looks like a pragma.
  @param pos offset to the first non-whitespace character
  of the rule.
  @param limit pointer past the last character of the rule.