https://mongodb.github.io/mongo-csharp-driver/2.12/apidocs/html/M_MongoDB_Driver_IAsyncCursorSourceExtensions_ToEnumerable__1.htm
IAsyncCursorSourceExtensions.ToEnumerable(TDocument) Method
Wraps a cursor source in an IEnumerable. Each time GetEnumerator is called a new cursor is fetched from the cursor source.
method