def _postpone_selected(self, p_pattern, p_mode):
        """
        Postpones selected todo item by <COUNT><PERIOD>.

        Returns True after 'postpone' command is called (i.e. p_pattern is valid
        <PERIOD>), False when p_pattern is invalid and None if p_pattern is
        digit (i.e. part of <COUNT>).

        p_pattern accepts digit (<COUNT>) or one of the <PERIOD> letters:
        'd'(ay), 'w'(eek), 'm'(onth), 'y'(ear). If digit is specified, it is
        appended to _pp_offset attribute. If p_pattern contains one of the
        <PERIOD> letters, 'postpone' command is forwarded to execution with
        value of _pp_offset attribute used as <COUNT>. If _pp_offset is None,
        <COUNT> is set to 1.

        p_mode should be one of 'postpone_s' or 'postpone'. It decides whether
        'postpone' command should be called with or without '-s' flag.
        """
        if p_pattern.isdigit():
            if not self._pp_offset:
                self._pp_offset = ''
            self._pp_offset += p_pattern
            result = None
        else:
            if p_pattern in ['d', 'w', 'm', 'y', 'b']:
                offset = self._pp_offset or '1'
                if p_mode == 'postpone':
                    pp_cmd = 'cmd postpone {} '
                else:
                    pp_cmd = 'cmd postpone -s {} '
                pp_cmd += offset + p_pattern
                self.resolve_action(pp_cmd)
                result = True
            self._pp_offset = None
            result = False
        return result
Postpones selected todo item by <COUNT><PERIOD>.

        Returns True after 'postpone' command is called (i.e. p_pattern is valid
        <PERIOD>), False when p_pattern is invalid and None if p_pattern is
        digit (i.e. part of <COUNT>).

        p_pattern accepts digit (<COUNT>) or one of the <PERIOD> letters:
        'd'(ay), 'w'(eek), 'm'(onth), 'y'(ear). If digit is specified, it is
        appended to _pp_offset attribute. If p_pattern contains one of the
        <PERIOD> letters, 'postpone' command is forwarded to execution with
        value of _pp_offset attribute used as <COUNT>. If _pp_offset is None,
        <COUNT> is set to 1.

        p_mode should be one of 'postpone_s' or 'postpone'. It decides whether
        'postpone' command should be called with or without '-s' flag.