Represents the contents of the original request that was passed to the [Streaming]DetectIntent 
call.
| JSON representation | 
|---|
| { "source" : string , "version" : string , "payload" : { object } } | 
| Fields | |
|---|---|
| source |   The source of this request, e.g.,  | 
| version |   Optional. The version of the protocol used for this request. This field is AoG-specific. | 
| payload |   Optional. This field is set to the value of the  In particular, for the Dialogflow Phone Gateway integration, this field has the form: {
 "telephony": {
   "caller_id": "+18558363987"
 }
}Note: The caller ID field (  | 

