anchor.diff:  
   + Response 200
   
  ++ Response 500 (application/json)
  +    
  +        {
  +            "errorMsg": "Deactivating user failed"
  +        }
  +
  +## User Nickname [/api/users/{user_id}/nickName]
  +
   ### Change User Nickname [PATCH]
   
   + Request (application/merge-patch+json)
  
positive.code: 
  Arij's project API
  
  ## Users collection [/api/users]
  
  ### List All Users [GET]
  
  
negative.code:           "nickName": "New Nickname Value" 
          }
          
  + Response 200
  
  
  + Response 500 (application/json)
      
          {
              "errorMsg": "Modifying user nick name user failed"
          }
          
  
  ## User Roles [/api/users/{user_id}/roles]
  
  ### Change User Roles [PATCH]
  
  + Request (application/merge-patch+json)
  
          { 
            "roles": ["newRole1", "newRoleN"] 
          }
          
  + Response 200
  
  
  + Response 500 (application/json)
      
          {
              "errorMsg": "Modifying user roles failed"