public function testSearchPostsByUsername()
 {
     $post_dao = new PostMySQLDAO();
     //should be first page of 20
     $results = $post_dao->searchPostsByUser(array('post'), 'twitter', 'ev');
     $this->assertEqual(sizeof($results), 20);
     //page 2
     $results = $post_dao->searchPostsByUser(array('post'), 'twitter', 'ev', 2);
     $this->assertEqual(sizeof($results), 19);
     //empty page 3
     $results = $post_dao->searchPostsByUser(array('post'), 'twitter', 'ev', 3);
     $this->assertEqual(sizeof($results), 0);
     //test and
     $results = $post_dao->searchPostsByUser(array('post', 'asdf'), 'twitter', 'ev');
     $this->assertEqual(sizeof($results), 0);
     $results = $post_dao->searchPostsByUser('keyword', 'twitter', 'ev');
     $this->assertEqual(sizeof($results), 0);
     //test with repeated keywords
     $results = $post_dao->searchPostsByUser(array('post', 'post'), 'twitter', 'ev');
     $this->assertEqual(sizeof($results), 0);
 }