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