Braintree\Test\Transaction::settlementDecline PHP Method

    public static function settlementDecline($transactionId)
    {
        return Configuration::gateway()->testing()->settlementDecline($transactionId);
    }

 public function testSettlementDeclined()
 {
     $transaction = Braintree\Transaction::saleNoValidate(['amount' => '100.00', 'creditCard' => ['number' => '5105105105105100', 'expirationDate' => '05/12'], 'options' => ['submitForSettlement' => true]]);
     $transaction = Braintree\Test\Transaction::settlementDecline($transaction->id);
     $this->assertEquals('settlement_declined', $transaction->status);
 }