public function testPoint1DEquals()
 {
     $point1D = new Point1D(1);
     $this->assertTrue($point1D->equals($point1D));
     $this->assertFalse($point1D->equals(new Point1D(1)));
     $this->assertFalse($point1D->equals(new Point1D(80)));
     $this->assertTrue($point1D->equals($point1D->move(-30)));
 }