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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 security():
 """View for security page."""

    sessions = SessionActivity.query_by_user(
        user_id=current_user.get_id()
    ).all()
    master_session = None
    for index, session in enumerate(sessions):
        if SessionActivity.is_current(session.sid_s):
            master_session = session
            del sessions[index]
    return render_template(
        current_app.config['ACCOUNTS_SETTINGS_SECURITY_TEMPLATE'],
        formclass=RevokeForm,
        sessions=[master_session] + sessions,
        is_current=SessionActivity.is_current
    )