public function setDefaultValueShouldProvideFluentInterfaceAndReallySetDefaultValue()
{
$returnedArgument = $this->simpleValueArgument->setDefaultValue('default');
$this->assertSame($this->simpleValueArgument, $returnedArgument, 'The returned argument is not the original argument.');
$this->assertSame('default', $this->simpleValueArgument->getDefaultValue());
}