anchor.diff:  
   # Group Lightning
   
  -## Retrieve lightning observation [?provider={provider1,provider2}&locationWithin={lonTopLeft,latTopLeft,lonBottomRight,latBottomRight}&occurredFrom={startTime}&occurredUntil={endTime}]
  +## Retrieve lightning observation [?provider={provider1,provider2}&locationWithin={lonTopLeft,latTopLeft,lonBottomRight,latBottomRight}&occurredFrom={startTime}&occurredUntil={endTime}&startPosition={startPosition}]
   ## Retrieve lightning observation [?provider={provider1,provider2}&locationWithin={lonTopLeft,latTopLeft,lonBottomRight,latBottomRight}&occurredFrom={startTime}]
   
   #### Example
  -https://lightning.weather.mg/search?provider=NOWCAST&locationWithin=[-10,80],[10,5]&occurredFrom=2017-01-05T12:21:14Z&occurredUntil=2017-01-05T12:21:15Z
  +https://lightning.weather.mg/search?provider=NOWCAST&locationWithin=[-10,80],[10,5]&occurredFrom=2017-01-05T12:21:14Z&occurredUntil=2017-01-05T12:21:15Z&startPosition=30000
   https://lightning.weather.mg/search?provider=NOWCAST&locationWithin=[-10,80],[10,5]&occurredFrom=2017-01-05T12:21:14Z
   https://lightning.weather.mg/search?provider=NOWCAST&locationWithin=[-10,80],[10,5]
   
   ##### Limitation
  -AWS service response can't be more than < 6MB because of technical limitations(AWS lambda)
  -If locationWithin is worldwide [-180, 90][180, -90] and occurrence ~3 days the response size is usually grater than 6MB.
  +AWS Lambda service response can have size < 6MB, it is about 30000 lightning events. If there are more than 30 000 results in storage which comply to the search criteria, they can be retrieved using pagination, by the use of startPosition parameter. In such case response contains Link header with the next startPosition offset.
  +If locationWithin is worldwide [-180, 90][180, -90] and occurrence ~3 days
  +
   
   ### Observed lightning for a given boundingBox and time period
   
  
positive.code:     + occurredUntil: `2017-01-05T12:21:15Z` (end time range, optional)
          - time range period for lightning observation.
  
  
      + provider: `ENGLN,NOWCAST' (string, required)
          - lightning providers.
  
  
  
  + Response 200 (application/json)
  
negative.code:     + Headers
  
              Authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWV9.EkN-DOsnsuRjRO6BxXemmJDm3HbxrbRzXglbN2S4sOkopdU4IsDxTI8jO19W_A4K8ZPJijNLis4EZsHeY559a4DFOd50_OqgHGuERTqYZyuhtF39yxJPAjUESwxk2J5k_4zM3O-vtd1Ghyo4IbqKKSy6J9mTniYJPenn5-HIirE
  			Link: <&startPosition=30000>; rel="next"
  
      + Body
          {
  