fn test_nested_array_of_string_references_compare_empty_in_mut_loop() {
    v1 := 'abc'
    v2 := 'def'
    mut sec_array := [][]&string{len: 1, init: []&string{}}
    sec_array[0] << &v1
    sec_array[0] << &v2
    mut found_non_empty := false
    for mut elem in sec_array {
        if elem != [] {
            found_non_empty = true
            assert elem.len == 2
            assert *elem[0] == 'abc'
            assert *elem[1] == 'def'
        }
    }
    assert found_non_empty
}