# Functions
NewBase64 returns a Base64 which accepts values which decode to len byte strings.
NewBase64List returns a Base64List which accepts a comma-separated list of strings which must decode to len byte strings.
SetFlagsFromEnv parses all registered flags in the given flagset, and if they are not already set it attempts to set their values from environment variables.
# Structs
Base64 implements flag.Value, and is used to populate []byte values from baes64 encoded strings.
Base64List implements flag.Value and is used to populate [][]byte values from a comma-separated list of base64 encoded strings.