def cache(name, value, created_on)
      meter = Meter.new(name: name, value: value, created_on: created_on, created_at: Time.now)
      store(name, meter)
    end
def cache(name, value, created_on)
      meter = Meter.new(name: name, value: value, created_on: created_on, created_at: Time.now)
      store(name, meter)
    end
Creates a new Meter and stores is in the hash