SnapshotSasPermissions
 SnapshotSasPermissions contains the list of
            permissions that can be set for a blob's access policy.  Use
             SetPermissions
            to set the permissions on the  BlobSasBuilder.
            
                using System;
namespace Azure.Storage.Sas
{
    [Flags]
    public enum SnapshotSasPermissions
    {
        Read = 1,
        Write = 2,
        Delete = 4,
        SetImmutabilityPolicy = 8,
        PermanentDelete = 16,
        All = -1
    }
}