Gets and sets the CallerReference property.
            A unique number that ensures the request can't be replayed.
            If the CallerReference is new (no matter the content of the 
            CloudFrontOriginAccessIdentityConfig object), a new distribution 
            is created. The default value set by the AWS SDK for NET is the 
            UtcNow timestamp.
            
 Declaration Syntax
 Declaration Syntax| C# | 
public string CallerReference { get; set; }
 Remarks
 RemarksIf the CallerReference is a value you already sent in a previous request to create an identity, and the content of the CloudFrontOriginAccessIdentityConfig is identical to the original request (ignoring white space), 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 an identity but the content of the CloudFrontOriginAccessIdentityConfig is different from the original request, CloudFront returns a CloudFrontOriginAccessIdentityAlreadyExists error.