What is the story of Cholkar and his vow to Sai Baba?

The story of Cholkar, detailed in Chapter 15, is about a man from a poor household whose livelihood depended on passing an examination. He made a vow to Sai Baba that if he passed, he would come to Shirdi and distribute sugar candy (khadisakhar). His wish was granted, but financial difficulties, described as a difficult 'threshold-ghat,' delayed his journey. As a form of penance during this delay, Cholkar gave up sugar completely. When he finally reached Shirdi and fulfilled his vow, Baba demonstrated his omniscience by telling a host to give Cholkar tea 'well-filled with sugar,' proving he knew the secret vow and sacrifice all along.