public function getItemType()
    {
        if (!preg_match('/array\<(.+)\>/i', $this->serializerType, $matches)) {
            return $this->serializerType;
        }

        $map = [
            'DateTime'  => 'date',
            'integer'   => 'int',
            'float'     => 'float',
            'double'    => 'float',
            'boolean'   => 'boolean',
            'extref'    => 'extref',
        ];
        return isset($map[$matches[1]]) ? $map[$matches[1]] : $matches[1];
    }