Comparison between class and function

    class ChannelType {
      constructor() { this.state = [] }
      state() { return this.state }
      take()  { this.state.push("take") }
      put()   { this.state.push("put") }
      flush() { this.state.push("flush") }
      close() { this.state.push("close") }
    }
    const channel = new ChannelType()
    // const channel = (function channel() {
    //   let state = []
    //   return {
    //     state: state,
    //     take: () => {state.push("take")},
    //     put: () => {state.push("put")},
    //     flush: () => {state.push("flush")},
    //     close: () => {state.push("close")}
    //   }
    // })()