Eugene Sirotkin

The [support of "*.exists" requests have been removed in version 3.0](http://support.zabbix.com/browse/ZBXNEXT-2724) of Zabbix. See [Zabbix API changes from 2.4 to 3.0](http://www.zabbix.com/documentation/3.0/manual/api/changes_2.4_-_3.0). Instead, it is suggested to use the "[*.get](http://www.zabbix.com/documentation/3.0/manual/api/reference/item/get)" methods.