<!-- Intent: verifies a contact with the given EntityGuid exists on list with listcode of 123456 GET to the following url http://api.v4.swiftreach.com/api/ContactLists/Contacts/Exists/123456/736c8340-e23b-4c23-aaa1-f55cfdb391bb --> <!-- No XML input is required --> <!-- example return value --> <int>true</int>