code: function ZarinPal(MerchantID, sandbox) {
  	if (typeof MerchantID === 'string' && MerchantID.length === config.merchantIDLength) {
  		this.merchant = MerchantID;
  	} else {
  		console.error('The MerchantID must be ' + config.merchantIDLength + ' Characters.');
  		return false;
  	}
  	this.sandbox = sandbox || false;
  
  	this.url = (sandbox === true) ? config.sandbox : config.https;
  }
docs: Constructor for ZarinPal object.
  @param {String} MerchantID
  @param {bool} sandbox