/// <summary>
        /// Add a ScraperTarget label.
        /// </summary>
        /// <param name="labelId">the ID of a label</param>
        /// <param name="scraperTargetId">the ID of a ScraperTarget</param>
        /// <returns>added label</returns>
        public async Task <Label> AddLabel(string labelId, string scraperTargetId)
        {
            Arguments.CheckNonEmptyString(scraperTargetId, nameof(scraperTargetId));
            Arguments.CheckNonEmptyString(labelId, nameof(labelId));

            var mapping = new LabelMapping(labelId);

            return(await _service.PostScrapersIDLabelsAsync(scraperTargetId, mapping).ContinueWith(t => t.Result.Label));
        }
        /// <summary>
        /// Add a ScraperTarget label.
        /// </summary>
        /// <param name="labelId">the ID of a label</param>
        /// <param name="scraperTargetId">the ID of a ScraperTarget</param>
        /// <returns>added label</returns>
        public async Task <Label> AddLabelAsync(string labelId, string scraperTargetId)
        {
            Arguments.CheckNonEmptyString(scraperTargetId, nameof(scraperTargetId));
            Arguments.CheckNonEmptyString(labelId, nameof(labelId));

            var mapping = new LabelMapping(labelId);

            var response = await _service.PostScrapersIDLabelsAsync(scraperTargetId, mapping).ConfigureAwait(false);

            return(response.Label);
        }