def set_custom_property(self,

                            name: str,

                            value: Any,

                            valuetype: Optional[str]=None,

    ) -> odf.meta.UserDefined:

        if valuetype is None:

            if isinstance(value, bool):

                valuetype = 'boolean'

            elif isinstance(value, (datetime.date, datetime.datetime)):

                valuetype = 'date'

            elif isinstance(value, (int, float, Decimal)):

                valuetype = 'float'

        if not isinstance(value, str):

            if valuetype == 'boolean':

                value = 'true' if value else 'false'

            elif valuetype == 'date':

                value = value.isoformat()

            else:

                value = str(value)

        retval = self.ensure_child(self.document.meta, odf.meta.UserDefined, name=name)

        if valuetype is None:

            try:

                retval.removeAttribute('valuetype')

            except KeyError:

                pass

        else:

            retval.setAttribute('valuetype', valuetype)

        retval.childNodes.clear()

        retval.addText(value)

        return retval