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