/**
  * @covers ::whereFunc
  */
 public function testWhereFunc()
 {
     $b = new WhereBuilder();
     $b->root('Author');
     $b->whereFunc(DB::avg('age'), '>', 30);
     $components = $b->build();
     $expr = new FuncExpr('age', 'AVG');
     $expr->setValue(['age']);
     $where = [['type' => 'Basic', 'table' => '_', 'cols' => [$expr], 'op' => '>', 'val' => 30, 'logic' => 'AND', 'not' => false]];
     $this->assertEquals($where, $components['where']);
 }