<?php

/**
 * @method \SplFixedArray a()
 */
class Demo {

    /**
     * @return \SplFixedArray
     */
    public static function __callStatic($name, $arguments = NULL)
    {
        return new SplFixedArray(5);
    }

}

Demo::a()->count(); // code completion for SplFixedArray works
Demo::b()->         // shows "no suggestions"

?>