function isPossibleRelativeReference(token, last, paramName) {
    return SYMBOL_START.exec(token.charAt(0)) &&
      token !== 'true' &&
      token !== 'false' &&
      token !== 'this' &&
      token !== paramName &&
      last !== '.'
  }
@param {string} token
@param {string|null} last
@param {string} paramName
@returns {boolean}