/// Base64 encoding character set.
///
/// Contains the 64 characters used in standard base64 encoding:
/// A-Z, a-z, 0-9, '+', and '/'.
pub(crate) const CHARS: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
