The IsSplitTestCampaign method tells you whether a campaign is a split test campaign or just a normal campaign.
||This is the username from your API key. It is in the format of an email address and will look similar to apiuser‑email@example.com
||This is the password from your API key.
||This is the ID of the campaign you wish to query against.
||TRUE if the campaign is a split test campaign, FALSE if it is not.