How to use the arc.getCachedAccount function in arc

public async componentDidMount (): Promise {
    /**
     * Heads up that there is a chance this cached account may differ from an account
     * that the user has already selected in a provider but have
     * not yet made available to the app.
     */
    const currentAddress = getCachedAccount();
    let accountWasCached = false;
    if (currentAddress) {
      accountWasCached = true;
      // eslint-disable-next-line no-console
      console.log(`using account from local storage: ${currentAddress}`);
    }

    this.props.setCurrentAccount(currentAddress);
    /**
     * Only supply currentAddress if it was obtained from a provider.  The poll
     * is only comparing changes with respect to the provider state.  Passing it a cached state
     * will only cause it to get the wrong impression and misbehave.
     */
    pollForAccountChanges(accountWasCached ? null : currentAddress).subscribe(
      (newAddress: Address | null): void => {
        // eslint-disable-next-line no-console