public function search($params)
 {
     $query = User::find()->where('status=0');
     $dataProvider = new ActiveDataProvider(['query' => $query]);
     if (!($this->load($params) && $this->validate())) {
         return $dataProvider;
     }
     $query->andFilterWhere(['id' => $this->id, 'role' => $this->role, 'status' => $this->status]);
     $query->andFilterWhere(['like', 'username', $this->username])->andFilterWhere(['like', 'firstname', $this->firstname])->andFilterWhere(['like', 'lastname', $this->lastname])->andFilterWhere(['like', 'email', $this->email]);
     return $dataProvider;
 }