def check_if_phone_number_is_opted_out(phoneNumber=None):
    """
    Accepts a phone number and indicates whether the phone holder has opted out of receiving SMS messages from your account. You cannot send SMS messages to a number that is opted out.
    To resume sending messages, you can opt in the number by using the OptInPhoneNumber action.
    See also: AWS API Documentation
    
    
    :example: response = client.check_if_phone_number_is_opted_out(
        phoneNumber='string'
    )
    
    
    :type phoneNumber: string
    :param phoneNumber: [REQUIRED]
            The phone number for which you want to check the opt out status.
            

    :rtype: dict
    :return: {
        'isOptedOut': True|False
    }
    
    
    """
    pass
