public function getArgumentNamesReturnsNamesOfAddedArguments()
{
$arguments = new Arguments();
$arguments->addNewArgument('first');
$arguments->addNewArgument('second');
$arguments->addNewArgument('third');
$expectedArgumentNames = ['first', 'second', 'third'];
$this->assertEquals($expectedArgumentNames, $arguments->getArgumentNames(), 'Returned argument names were not as expected.');
}