Phalcon\Mvc\Model\Resultset::serialize() returns string, no array

[Chealer]

The documentation of Phalcon\Mvc\Model\Resultset pretty much says that serialize() returns "a big array":

Serializing a resultset will dump all related rows into a big array

As one may guess, this is in fact incorrect, as behavior shows it returns a string, as its synopsis indicates:

public function serialize(): string;

It would help to make the documentation more formal.