How to use the blockstack.handlePendingSignIn 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))
  }

componentWillMount() {
    if (isSignInPending()) {
      handlePendingSignIn().then(userData => {
        window.location = window.location.origin;
      });
    }
    // this.enableTab('textarea1');
  }

componentDidMount() {
    if (isSignInPending()) {
      handlePendingSignIn().then((userData) => {
        window.location = window.location.href.split('&')[0];
      });
    }
    isUserSignedIn() ? this.props.loadInvite() : loadUserData();
  }

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() {
    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 + "?blockstack";
      });
    }
  }