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