/// <summary> /// Adds a test filter if not already added. /// </summary> /// <param name="filter">The filter to add.</param> /// <exception cref="ArgumentNullException">Thrown if <paramref name="filter"/> is null.</exception> public void AddTestFilter(FilterInfo filter) { if (filter == null) { throw new ArgumentNullException("filter"); } filter.Validate(); if (!testFilters.Contains(filter)) { testFilters.Add(filter); } }