How to use the @jupyterlab/terminal.Terminal function in @jupyterlab/terminal

async function main(): Promise {
  let dock = new DockPanel();
  dock.id = 'main';

  // Attach the widget to the dom.
  Widget.attach(dock, document.body);

  // Handle resize events.
  window.addEventListener('resize', () => {
    dock.fit();
  });

  const manager = new TerminalManager();
  const s1 = await manager.startNew();
  const term1 = new Terminal(s1, { theme: 'light' });
  term1.title.closable = true;
  dock.addWidget(term1);

  const s2 = await manager.startNew();
  const term2 = new Terminal(s2, { theme: 'dark' });
  term2.title.closable = true;
  dock.addWidget(term2, { mode: 'tab-before' });

  console.log('Example started!');
}

// Attach the widget to the dom.
  Widget.attach(dock, document.body);

  // Handle resize events.
  window.addEventListener('resize', () => {
    dock.fit();
  });

  const manager = new TerminalManager();
  const s1 = await manager.startNew();
  const term1 = new Terminal(s1, { theme: 'light' });
  term1.title.closable = true;
  dock.addWidget(term1);

  const s2 = await manager.startNew();
  const term2 = new Terminal(s2, { theme: 'dark' });
  term2.title.closable = true;
  dock.addWidget(term2, { mode: 'tab-before' });

  console.log('Example started!');
}

private async setupTerminalSession() {
        // Abort if somehow no terminals available.
        if (!this.app.serviceManager.terminals.isAvailable()) {
            // tslint:disable-next-line:no-console
            console.log("Disabling jupyterlab_black plugin because lack of terminal access.");
            this.loaded = false;
            return;
        }

        this.term = new Terminal();

        try {
            this.term.session = await this.app.serviceManager.terminals.startNew();
            // NOTE: unset HISTFILE so user's shell history is no longer as polluted
            //       when we dump codecell content though terminal.
            this.term.session.send({type: "stdin", content: ["unset HISTFILE\r"]});
            this.loaded = true;
            // tslint:disable-next-line:no-console
            console.log("Terminal session started.", this.term.session.name);
        } catch (e) {
            this.term.dispose();
            this.term = undefined;
            this.loaded = false;
        }
    }

async load_linter(){

    // Bail if there are no terminals available.
    if (!this.app.serviceManager.terminals.isAvailable()) {
      console.log('Disabling jupyterlab-flake8 plugin because it cant access terminal');
      this.loaded = false;
      this.toggled = false;
      return;
    }

    this.term = new Terminal();
    try {
      this.term.session = await this.app.serviceManager.terminals.startNew();
      console.log('loaded terminal session');

      // wait 2 seconds for terminal to load and get initial commands out of its system
      setTimeout(() => {
        this.check_flake8();
      }, 2000)
    }
    catch(e) {
      this.term.dispose();
      this.term = undefined;
    }
  }

function main(): void {
  let term1 = new Terminal({ theme: 'light' });
  let term2 = new Terminal({ theme: 'dark' });

  TerminalSession.startNew().then(session => {
    term1.session = session;
  });
  TerminalSession.startNew().then(session => {
    term2.session = session;
  });

  term1.title.closable = true;
  term2.title.closable = true;
  let dock = new DockPanel();
  dock.addWidget(term1);
  dock.addWidget(term2, { mode: 'tab-before' });
  dock.id = 'main';

  // Attach the widget to the dom.

execute: args => {
      let name = args ? args['name'] as string : '';
      let term = new Terminal();
      term.title.closable = true;
      term.title.icon = TERMINAL_ICON_CLASS;
      term.title.label = '...';
      shell.addToMainArea(term);

      let promise = name ?
        services.terminals.connectTo(name)
        : services.terminals.startNew();

      return promise.then(session => {
        term.session = session;
        tracker.add(term);
        shell.activateById(term.id);
        return term;
      }).catch(() => { term.dispose(); });
    }

function main(): void {
  let term1 = new Terminal({ theme: 'light' });
  let term2 = new Terminal({ theme: 'dark' });

  TerminalSession.startNew().then(session => {
    term1.session = session;
  });
  TerminalSession.startNew().then(session => {
    term2.session = session;
  });

  term1.title.closable = true;
  term2.title.closable = true;
  let dock = new DockPanel();
  dock.addWidget(term1);
  dock.addWidget(term2, { mode: 'tab-before' });
  dock.id = 'main';