Braintree\Gateway::merchantAccount PHP Method

    public function merchantAccount()
    {
        return new MerchantAccountGateway($this);
    }

 public function testGatewayCreate()
 {
     $gateway = new Braintree\Gateway(array('environment' => 'development', 'merchantId' => 'integration_merchant_id', 'publicKey' => 'integration_public_key', 'privateKey' => 'integration_private_key'));
     $result = $gateway->merchantAccount()->create(self::$validParams);
     $this->assertEquals(true, $result->success);
     $merchantAccount = $result->merchantAccount;
     $this->assertEquals(Braintree\MerchantAccount::STATUS_PENDING, $merchantAccount->status);
     $this->assertEquals("sandbox_master_merchant_account", $merchantAccount->masterMerchantAccount->id);
 }