Function parallel_for_each 

pub fn parallel_for_each<T, F>(
    taskflow: &mut Taskflow,
    data: Vec<T>,
    chunk_size: usize,
    func: F,
) -> Vec<TaskHandle>
where
    T: Send + 'static,
    F: Fn(T) + Send + Sync + Clone + 'static,

Parallel for_each - applies a function to each element in parallel