Generator that yields filtered and/or sorted :class:`Si` instances
        from ``self.sic``.

        :param specfiles: filenames of ms-run files - if specified return only
            items from those files
        :type specfiles: str or [str, str, ...]
        :param sort: if "sort" is specified the returned list of items is sorted
            according to the :class:`Si` attribute specified by "sort", if the
            attribute is not present the item is skipped.
        :param reverse: bool, ``True`` reverses the sort order
        :param selector: a function which is called with each ``Si`` item
            and returns True (include item) or False (discard item). Default
            function is: ``lambda si: True``

        :returns: items from container that passed the selector function

def getItems(self, specfiles=None, sort=False, reverse=False,
                 selector=None):
        """Generator that yields filtered and/or sorted :class:`Si` instances
        from ``self.sic``.

        :param specfiles: filenames of ms-run files - if specified return only
            items from those files
        :type specfiles: str or [str, str, ...]
        :param sort: if "sort" is specified the returned list of items is sorted
            according to the :class:`Si` attribute specified by "sort", if the
            attribute is not present the item is skipped.
        :param reverse: bool, ``True`` reverses the sort order
        :param selector: a function which is called with each ``Si`` item
            and returns True (include item) or False (discard item). Default
            function is: ``lambda si: True``

        :returns: items from container that passed the selector function
        """
        selector = (lambda si: True) if selector is None else selector
        if specfiles is None:
            specfiles = [_ for _ in viewkeys(self.info)]
        else:
            specfiles = aux.toList(specfiles)
        return _getItems(self.sic, specfiles, sort, reverse, selector)