public function testCompare()
 {
     $binding1 = new BindingDescriptor('/vendor/a', 'vendor/a-type');
     $binding2 = new BindingDescriptor('/vendor/a', 'vendor/b-type');
     $binding3 = new BindingDescriptor('/vendor/b', 'vendor/a-type');
     $this->assertSame(0, BindingDescriptor::compare($binding1, $binding1));
     $this->assertSame(0, BindingDescriptor::compare($binding2, $binding2));
     $this->assertLessThan(0, BindingDescriptor::compare($binding1, $binding2));
     $this->assertGreaterThan(0, BindingDescriptor::compare($binding2, $binding1));
     $this->assertLessThan(0, BindingDescriptor::compare($binding1, $binding3));
     $this->assertGreaterThan(0, BindingDescriptor::compare($binding3, $binding1));
     $this->assertLessThan(0, BindingDescriptor::compare($binding2, $binding3));
     $this->assertGreaterThan(0, BindingDescriptor::compare($binding3, $binding2));
 }