pub struct DirectoryHandle {
    child_paths: Vec<String>,
    finished: bool,
}
impl DirectoryHandle {
    pub fn get_files(&mut self) -> Result<Vec<String>, String> {
        if self.finished {
            Err("Could not find more files.".to_string())
        } else {
            self.finished = true;
            Ok(self.child_paths.clone())
        }
    }
    pub fn new(childs: Vec<String>) -> DirectoryHandle {
        DirectoryHandle {
            child_paths: childs,
            finished: false,
        }
    }
}