code: function verifyFormToken(formToken) {
  		/*jshint validthis:true */
  		checkSecure(this);
  
  		// If we already cached this token, we know that it's valid.
  		// If we validate two different tokens for the same request,
  		// this won't incorrectly skip the second one.
  		if (this.res._csrfFormToken && this.res._csrfFormToken === formToken)
  			return true;
  
  		this._csrfChecked = true;
  		if (!formToken) return false;
  
  		var cookieToken = getCookieToken(this.res);
  		if (!cookieToken) return false;
  
  		var parts = formToken.split('|');
  
  		// If the token is invalid, reject it.
  		if (parts.length !== 2)
  			return false;
  
  		var hasher = crypto.createHmac(options.algorithm, formKey);
  		hasher.update(cookieToken);
  		hasher.update("|");	// Don't confuse longer or shorter tokens
  		hasher.update(parts[0]);
  
  		// If the hash doesn't match, reject the token
  		if (parts[1] !== hasher.digest('base64'))
  			return false;
  
  		// If we have a valid token, reuse it for this request
  		// instead of generating a new one. (saves crypto ops)
  		if (!this.res._csrfFormToken)
  			this.res._csrfFormToken = formToken;
  
  		return true;
  	}
docs: Verifies a form token submitted with the current request.
  This function must be called on the request object.
  
  @returns {Boolean} True if the form token matches the cookie in the request.