Gets the usergroups a user or the current logged in user can read.
| Webservice Type: | REST | 
| Output format: | Json | 
| Request method: | GET | 
| Mandatory parameters: | none | 
| Optional parameters: | userName: username of he user to obtain readable groups from. If this is not set, the readable groups of the currently logged in user are returned. | 
| Examples: | 
            Get @ http://sapsailing.com/security/api/restsecurity/usergroup/readable
             Example payload: 
{
    "readableGroups": [
        {
            "uuid": "96759067-7090-413d-94c5-8367c2e34b9f",
            "name": "group2ToAdd",
            "roles": []
        },
        {
            "uuid": "a8f98697-6d74-42da-b516-430279d9dadd",
            "name": "user1-tenant",
            "roles": []
        }
    ]
}
         |