{"ast_node_type":"variable","tokens":[{"end":43,"kind":"keyword","start":0,"text":"let"}]}
    let mut buf = [0u8; size_of::<u128>()];
    // This u128 holds an "any-size uint" (since smaller uints can fits in it)
    // So we do not read exactly 16 bytes into the u128, just the "payload".