Macro dbgbb_concat 

macro_rules! dbgbb_concat {
    ($x:expr, depth => 1) => { ... };
    ($x:expr, depth => 2) => { ... };
    ($x:expr, depth => 3) => { ... };
    ($x:expr, depth => 4) => { ... };
}

Create a single array and send it to the server. The lengths of the elements should be the same.

Usage:

use dbgbb::dbgbb_concat;
let a = vec![vec![1u32, 2], vec![3, 4]];
dbgbb_concat!(a, depth => 1);