public function addAnd($expression)
{
if (!isset($this->query['$and'])) {
$this->query['$and'] = [];
}
$this->query['$and'] = array_merge($this->query['$and'], array_map(function ($expression) {
return $expression instanceof Expr ? $expression->getQuery() : $expression;
}, func_get_args()));
return $this;
}