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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def handle_profile_form(form):
 """Handle profile update form."""

    form.process(formdata=request.form)

    if form.validate_on_submit():
        email_changed = False
        with db.session.begin_nested():
            # Update profile.
            current_userprofile.username = form.username.data
            current_userprofile.full_name = form.full_name.data
            db.session.add(current_userprofile)

            # Update email
            if current_app.config['USERPROFILES_EMAIL_ENABLED'] and \
               form.email.data != current_user.email:
                current_user.email = form.email.data
                current_user.confirmed_at = None
                db.session.add(current_user)
                email_changed = True
        db.session.commit()

        if email_changed:
            send_confirmation_instructions(current_user)
            # NOTE: Flash message after successful update of profile.
            flash(_('Profile was updated. We have sent a verification '
                    'email to %(email)s. Please check it.',
                    email=current_user.email),
                  category='success')
        else:
            # NOTE: Flash message after successful update of profile.
            flash(_('Profile was updated.'), category='success')