is(scalar(@tmp), 1, 'got one part even w/o boundary');
is($tmp[0]->[0]->[0]->body, "hello world\n", 'body preserved');
is($tmp[0]->[0]->[1], 0, '$depth is zero');
is(scalar(@tmp), 1, 'got one part even w/o boundary');
is($tmp[0]->[0]->[0]->body, "hello world\n", 'body preserved');
is($tmp[0]->[0]->[1], 0, '$depth is zero');