/**
*
*/
public function testIncrementAge()
{
//Create an Object to test with.
//We're creating an Animal object because the tested functionality is inherited by 'Dog' and 'Cat'
$animal = new Animal('Animal', 1);
//Speak once
$animal->speak("test");
//Our age should still be 1
$this->assertEquals(1, $animal->age());
//Speak twice
$animal->speak("test");
//Now our age should be 2
$this->assertEquals(2, $animal->age());
}