217 sub read_expect {
218     my $class = shift;
219     my($ssh, $type) = @_;
220     my $pack = $class->read($ssh);
221     if ($pack->type != $type) {
222         $ssh->fatal_disconnect(sprintf
223           "Protocol error: expected packet type %d, got %d",
224             $type, $pack->type);
225     }
226     $pack;
227 }