@rule('<STR_LIT>')<EOL><INDENT>def visit_dotted_filter(self, _, children):<DEDENT>
return children[<NUM_LIT:1>]<EOL>
A filter, preceded by a dot, could be a number (not a full slice) or a filter.

        Arguments
        ---------
        _ (node) : parsimonious.nodes.Node.
        children : list
            - 0: for ``DOT`` (a dot): ``None``.
            - 1: a ``Filter`` or ``SliceFilter`` (with only ``index`` set)

        Returns
        -------
        Filter or SliceFilter
            An instance of ``Filter`` if a filter, or ``SliceFilter`` if a number.

        Example
        -------

        >>> FiltersWithSlicingParserMixin('.1', default_rule='DOTTED_FILTER').data
        [1]
        >>> FiltersWithSlicingParserMixin('.foo', default_rule='DOTTED_FILTER').data
        .foo