Sourceval to_value :
Event.t list->[> `List of
[> `Structure of
(string
* [> `Enum of string| `List of
[> `Structure of
(string * [> `String of EventResourceType.t ]) list ]
list| `String of EventId.t| `Structure of
(string
* [> `List of
[> `Structure of
(string
* [> `List of [> `String of TagValue.t ] list| `String of AppBoundaryKey.t ])
list ]
list| `Structure of
(string * [> `List of [> `String of StackName.t ] list ])
list ])
list| `Timestamp of Timestamp.t ])
list ]
list ]