+ cargo test --all-features -- --nocapture
     Running tests/main.rs (target/debug/deps/main-8af48d1761c45bbe)
[tests/main.rs:7] &b64 = "AQID"
[tests/main.rs:8] b64d(b64).unwrap() = [
    1,
    2,
    3,
]
[tests/main.rs:11] &u64_b64 = "6hawTAI"
[tests/main.rs:12] b64_u64(u64_b64) = 9876543210