public function testGetMaxRank()
 {
     $this->assertEquals(4, Table12Query::create()->getMaxRank(1), 'getMaxRank() returns the maximum rank in the scope');
     $this->assertEquals(2, Table12Query::create()->getMaxRank(2), 'getMaxRank() returns the maximum rank in the scope');
     // delete one
     $t4 = Table12Query::create()->findOneByRank(4, 1);
     $t4->delete();
     $this->assertEquals(3, Table12Query::create()->getMaxRank(1), 'getMaxRank() returns the maximum rank');
     // add one
     $t = new Table12();
     $t->setMyScopeColumn(1);
     $t->save();
     $this->assertEquals(4, Table12Query::create()->getMaxRank(1), 'getMaxRank() returns the maximum rank');
     // delete all
     Table12Query::create()->deleteAll();
     $this->assertNull(Table12Query::create()->getMaxRank(1), 'getMaxRank() returns null for empty tables');
     // add one
     $t = new Table12();
     $t->setMyScopeColumn(1);
     $t->save();
     $this->assertEquals(1, Table12Query::create()->getMaxRank(1), 'getMaxRank() returns the maximum rank');
 }