private void consumeNonExecutePrefix() throws IOException {
    // fast forward through the leading whitespace
    nextNonWhitespace(true);
    pos--;

    if (pos + NON_EXECUTE_PREFIX.length > limit && !fillBuffer(NON_EXECUTE_PREFIX.length)) {
      return;
    }

    for (int i = 0; i < NON_EXECUTE_PREFIX.length; i++) {
      if (buffer[pos + i] != NON_EXECUTE_PREFIX[i]) {
        return; // not a security token!
      }
    }

    // we consumed a security token!
    pos += NON_EXECUTE_PREFIX.length;
  }