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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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