public function testIsPrimaryKeyNullCompmosite()
 {
     $b = new BookOpinion();
     $this->assertTrue($b->isPrimaryKeyNull());
     $b->setPrimaryKey(array(123, 456));
     $this->assertFalse($b->isPrimaryKeyNull());
     $b->setPrimaryKey(array(123, null));
     $this->assertFalse($b->isPrimaryKeyNull());
     $b->setPrimaryKey(array(null, 456));
     $this->assertFalse($b->isPrimaryKeyNull());
     $b->setPrimaryKey(array(null, null));
     $this->assertTrue($b->isPrimaryKeyNull());
 }