{ 
	my $pseudo;
	my @frags;
	sub set{
	    my( $frag, $offset, @meta ) = @_;
	    push @frags, Fragment->new( $frag, @meta );
	    $pseudo .= pack( 'v', $#frags ) x length( $frag );
	    return $frags[ -1 ];
	}
	sub find{
	    my $offset = @_;
	    my $index = unpack( 'v', substr( $pseudo, $offset, 2 ) );
	    return $frags[ $index ];
	}
}