A hash key value for the starting hash key of one of the child shards created by the split. The hash key range for a given shard constitutes
            a set of ordered contiguous positive integers. The value for NewStartingHashKey must be in the range of hash keys being mapped into
            the shard. The NewStartingHashKey hash key value and all higher hash key values in hash key range are distributed to one of the child
            shards. All the lower hash key values in the range are distributed to the other child shard.
             
            
Constraints:
 Declaration Syntax
 Declaration Syntax| C# | 
public string NewStartingHashKey { get; set; }