class Regexp::Expression::CharacterSet::Range

def <<(exp)

def <<(exp)
  complete? && raise("Can't add more than 2 expressions to a Range")
  super
end

def complete?

def complete?
  count == 2
end

def starts_at

def starts_at
  expressions.first.starts_at
end

def to_s(_format = :full)

def to_s(_format = :full)
  expressions.join(text)
end