pub const max_binary_custom_code: Int = 0xff

pub const min_binary_custom_code: Int = 0x80

pub fn from_bit_string_with_code(code: Int, value: BitString) -> Result(
  Custom,
  Nil,
)

pub fn to_bit_string_with_code(custom: Custom) -> #(
  Int,
  BitString,
)