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