public void onActivityCreated()

in auth/src/main/java/com/firebase/ui/auth/ui/email/CheckEmailFragment.java [116:176]
50 lines of code
11 McCabe index (conditional complexity)

    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        mHandler = new ViewModelProvider(this).get(CheckEmailHandler.class);
        mHandler.init(getFlowParams());

        FragmentActivity activity = getActivity();
        if (!(activity instanceof CheckEmailListener)) {
            throw new IllegalStateException("Activity must implement CheckEmailListener");
        }
        mListener = (CheckEmailListener) activity;

        mHandler.getOperation().observe(getViewLifecycleOwner(), new ResourceObserver<User>(
                this, R.string.fui_progress_dialog_checking_accounts) {
            @Override
            protected void onSuccess(@NonNull User user) {
                String email = user.getEmail();
                String provider = user.getProviderId();

                mEmailEditText.setText(email);
                //noinspection ConstantConditions new user
                if (provider == null) {
                    mListener.onNewUser(new User.Builder(EmailAuthProvider.PROVIDER_ID, email)
                            .setName(user.getName())
                            .setPhotoUri(user.getPhotoUri())
                            .build());
                } else if (provider.equals(EmailAuthProvider.PROVIDER_ID)
                        || provider.equals(EMAIL_LINK_PROVIDER)) {
                    mListener.onExistingEmailUser(user);
                } else {
                    mListener.onExistingIdpUser(user);
                }
            }

            @Override
            protected void onFailure(@NonNull Exception e) {
                if (e instanceof FirebaseUiException
                        && ((FirebaseUiException) e).getErrorCode() == ErrorCodes.DEVELOPER_ERROR) {
                    mListener.onDeveloperFailure(e);
                }

                if (e instanceof FirebaseNetworkException) {
                    Snackbar.make(getView(), getString(R.string.fui_no_internet), Snackbar.LENGTH_SHORT).show();
                }

                // Otherwise just let the user enter their data
            }
        });

        if (savedInstanceState != null) {
            return;
        }

        // Check for email
        String email = getArguments().getString(ExtraConstants.EMAIL);
        if (!TextUtils.isEmpty(email)) {
            mEmailEditText.setText(email);
            validateAndProceed();
        } else if (getFlowParams().enableHints) {
            mHandler.fetchCredential();
        }
    }