def enableSync(self, url, definition = None):
        """Enables Sync capability for an AGOL feature service.

        Args:
            url (str): The URL of the feature service.
            definition (dict): A dictionary containing valid definition values. Defaults to ``None``.
        Returns:
            dict: The result from :py:func:`arcrest.hostedservice.service.AdminFeatureService.updateDefinition`.

        """
        adminFS = AdminFeatureService(url=url, securityHandler=self._securityHandler)

        cap = str(adminFS.capabilities)
        existingDef = {}
        enableResults = 'skipped'
        if 'Sync' in cap:
            return "Sync is already enabled"
        else:
            capItems = cap.split(',')
            capItems.append('Sync')
            existingDef['capabilities'] = ','.join(capItems)
            enableResults = adminFS.updateDefinition(json_dict=existingDef)

            if 'error' in enableResults:
                return enableResults['error']
        adminFS = None
        del adminFS
        return enableResults
Enables Sync capability for an AGOL feature service.

        Args:
            url (str): The URL of the feature service.
            definition (dict): A dictionary containing valid definition values. Defaults to ``None``.
        Returns:
            dict: The result from :py:func:`arcrest.hostedservice.service.AdminFeatureService.updateDefinition`.