def to_s
      pretty_name = @name.to_s.split(/_/).map(&:capitalize).join(" ")
      on_or_off = on? ? "on" : "off"
      reachable = reachable? ? "reachable" : "unreachable"
      "#{pretty_name} is #{on_or_off} and #{reachable}"
    end
def to_s
      pretty_name = @name.to_s.split(/_/).map(&:capitalize).join(" ")
      on_or_off = on? ? "on" : "off"
      reachable = reachable? ? "reachable" : "unreachable"
      "#{pretty_name} is #{on_or_off} and #{reachable}"
    end
pretty-print the light's status