Gets and sets the property CallerReference. A unique name that ensures the request
can't be replayed. If the CallerReference is new (no matter the content of the
Path object), a new distribution is created. If the CallerReference is a value
you already sent in a previous request to create an invalidation batch, and the content
of each Path element is identical to the original request, the response includes
the same information returned to the original request. If the CallerReference is
a value you already sent in a previous request to create a distribution but the content
of any Path is different from the original request, CloudFront returns an InvalidationBatchAlreadyExists
error.

C# |
public string CallerReference { get; set; }