How to use the blockstack.isSignInPending function in blockstack

componentDidMount() {
    if (isSignInPending()) {
      handlePendingSignIn().then((userData) => {
        window.location = window.location.href.split('=?')[0];
      });
    }
    // console.log(decodeToken(JSON.parse(localStorage.blockstack).authResponseToken).payload.public_keys[0])
    // console.log(new TokenVerifier('ES256K', decodeToken(JSON.parse(localStorage.blockstack).authResponseToken).payload.public_keys[0]).verify(JSON.parse(localStorage.blockstack).authResponseToken))
  }

render() {
    const loading = false;
    const error = false;
    return !isSignInPending() ? (
      <div>
        <nav>
        <h1>Edit Contact</h1>
        <form> {
            e.preventDefault();
            this.handleEditContactSubmit(e);
          }}
        &gt;
          
          <fieldset>
            <label>
              Name
              </label></fieldset></form></nav></div>

componentWillMount() {
    if (isSignInPending()) {
      handlePendingSignIn().then(userData => {
        window.location = window.location.origin;
      });
    }
  }

render() {
    const loading = this.props.loading;
    const save = this.props.save;
    return (
      !isSignInPending() ?
      <div>
        <div>
          <div>
            <div>
            <h5>
              Delete File
            </h5>
            <h6>Are you sure you want to delete <strong>{this.props.name}</strong>?
            </h6>
            <div>
            <button>
              Delete
            </button>
            <a href="/vault"><button>
              No, go back
            </button></a></div></div></div></div></div>

componentWillMount() {
    if (isSignInPending()) {
      handlePendingSignIn().then(userData => {
        window.location = window.location.origin;
      });
    }
  }

componentWillMount() {
    if (isSignInPending()) {
      handlePendingSignIn().then(userData => {
        window.location = window.location.origin;
      });
    }
  }

componentWillMount() {
    if (isSignInPending()) {
      handlePendingSignIn().then(userData => {
        window.location = window.location.origin;
      });
    }
  }

componentWillMount() {
    if (isSignInPending()) {
      handlePendingSignIn().then(userData => {
        window.location = window.location.origin;
      });
    }
  }

componentWillMount() {
    this.analyticsRun = analyticsRun.bind(this);
    if (isSignInPending()) {
      handlePendingSignIn().then(userData => {
        window.location = window.location.origin;
      });
    }
  }
  componentDidMount() {

componentWillMount() {
    if (isSignInPending()) {
      handlePendingSignIn().then(userData => {
        window.location = window.location.origin;
      });
    }
  }