/// <summary>
/// Extract the changeset id from the change set boundary string.
/// This is the reversal method of <code>CreateChangeSetBoundary(bool, string)</code>.
/// </summary>
/// <param name="changesetBoundary">Change set boundary string previous constructed by <code>CreateChangeSetBoundary</code>.
/// Can be null.</param>
/// <returns>The change set id or null.</returns>
internal static string GetChangeSetIdFromBoundary(string changesetBoundary)
{
if (changesetBoundary == null)
{
return(null);
}
// The changeset boundary can be for either request or response, which are both constructed from templates.
// Change set id is the remainder after first char of '_'.
int idx = changesetBoundary.IndexOf('_');
ExceptionUtils.CheckIntegerNotNegative(idx, "idxOfSeparator");
return(changesetBoundary.Substring(idx + 1));
}