+=back
+
+The OO interface has these methods:
+
+=over
+
+=item Digest::HighwayHash->B<new>(I<\@key>)
+
+Initialize a new C<Digest::HighwayHash> state with a given key. The
+B<append> method will be called with this state and parts of the
+message, and then one of the B<finish*> methods will be called to
+compute the result.
+
+=item $state->B<append>(I<$input>)
+
+Append I<$input> to the message to be hashed by $state.
+
+=item $state->B<finish64>
+
+=item $state->B<finish128>
+
+=item $state->B<finish256>
+
+Compute and return the 64-bit, 128-bit, or respectively 256-bit
+HighwayHash of this state. The return values are the same as in the
+procedural interface.
+