Send a message to a Pushover user or group.
    :param sound:       The sound that we want to verify
    :param token:       The PushOver token.

def validate_sound(sound,
                   token):
    '''
    Send a message to a Pushover user or group.
    :param sound:       The sound that we want to verify
    :param token:       The PushOver token.
    '''
    ret = {
            'message': 'Sound is invalid',
            'res': False
           }
    parameters = dict()
    parameters['token'] = token

    response = query(function='validate_sound',
                     method='GET',
                     query_params=parameters)

    if response['res']:
        if 'message' in response:
            _message = response.get('message', '')
            if 'status' in _message:
                if _message.get('dict', {}).get('status', '') == 1:
                    sounds = _message.get('dict', {}).get('sounds', '')
                    if sound in sounds:
                        ret['message'] = 'Valid sound {0}.'.format(sound)
                        ret['res'] = True
                    else:
                        ret['message'] = 'Warning: {0} not a valid sound.'.format(sound)
                        ret['res'] = False
                else:
                    ret['message'] = ''.join(_message.get('dict', {}).get('errors'))
    return ret