# assert "string".encode_base64 == "c3RyaW5n"
private fun encode_base64(length: Int, padding: nullable Byte): Bytes do
var base64_bytes = once base64_chars
# assert "string".encode_base64 == "c3RyaW5n"
private fun encode_base64(length: Int, padding: nullable Byte): Bytes do
var base64_bytes = once base64_chars