public function testEquality()
 {
     $p1 = new Point(10, 10);
     $p2 = new Point(10, 10);
     $p3 = new Point(100, 100);
     $this->assertTrue($p1->equals($p2));
     $this->assertTrue($p2->equals($p1));
     $this->assertFalse($p1->equals($p3));
     $this->assertFalse($p3->equals($p1));
     $this->assertFalse($p3->equals(1337));
     $this->assertTrue($p3->equals($p3));
 }