/// <summary>
        /// Format and store an iKey and appId pair into the dictionary of known correlation ids.
        /// </summary>
        /// <param name="ikey">Instrumentation Key is expected to be a Guid string.</param>
        /// <param name="appId">Application Id is expected to be a Guid string. App Id needs to be Http Header safe, and all non-ASCII characters will be removed.</param>
        private void GenerateCorrelationIdAndAddToDictionary(string ikey, string appId)
        {
            if (string.IsNullOrWhiteSpace(appId))
            {
                return;
            }

            appId = HeadersUtilities.SanitizeString(appId);
            if (!string.IsNullOrEmpty(appId))
            {
                this.knownCorrelationIds[ikey] = string.Format(CultureInfo.InvariantCulture, CorrelationIdFormat, appId);
            }
        }
        /// <summary>
        /// Format and store an iKey and appId pair into the dictionary of known correlation ids.
        /// </summary>
        /// <param name="ikey">Instrumentation Key is expected to be a Guid string.</param>
        /// <param name="appId">Application Id is expected to be a Guid string. App Id needs to be Http Header safe, and all non-ASCII characters will be removed.</param>
        /// <remarks>To protect against injection attacks, AppId will be truncated to a maximum length.</remarks>
        private void GenerateCorrelationIdAndAddToDictionary(string ikey, string appId)
        {
            // Arbitrary maximum length to guard against injections.
            appId = StringUtilities.EnforceMaxLength(appId, InjectionGuardConstants.AppIdMaxLengeth);

            if (string.IsNullOrWhiteSpace(appId))
            {
                return;
            }

            appId = HeadersUtilities.SanitizeString(appId);
            if (!string.IsNullOrEmpty(appId))
            {
                this.knownCorrelationIds[ikey] = string.Format(CultureInfo.InvariantCulture, CorrelationIdFormat, appId);
            }
        }