The interface is configured to provide access to {HEAD ~ the data elements} and {TAIL ~ the order keys} in the dataset in a type safe manner 
The interface is configured to provide access to { HEAD ~ the data elements } and { TAIL ~ the order keys } in the dataset in a type safe manner
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH