An efficient Patricia tree implementation that maps strict 'ByteString's
to values.

The interface for this module is intended to look similar to that for
'Data.Map' and 'Data.IntMap', where appropriate. It differs from
'Data.Map' in the restriction of the key type to 'ByteString's, its
functions for looking up all prefixes of a key, and improved looked up
performance. It differs from 'Data.IntMap' in that it supports variable
length keys.