getObject(ApiClient::class); $result = $this->invokeInaccessibleMethod($vertex, 'getTotalTax', ['TotalTax' => 5]); $this->assertEquals(5, $result); } public function testGetTotalTaxReturnsZeroWithoutTotalTax() { $vertex = $this->getObject(ApiClient::class); $result = $this->invokeInaccessibleMethod($vertex, 'getTotalTax', ['some garbage data']); $this->assertEquals(0, $result); } }