Can you summarize the story of Cholkar's vow to Sai Baba and its fulfillment?

The story of Cholkar revolves around a vow he made to Sai Baba. As a poor man needing to pass an examination to secure his job, Cholkar promised that if he succeeded by Baba's grace, he would visit Shirdi and distribute sugar candy. Chapter 15 recounts that after he passed, financial hardship delayed his pilgrimage. As a personal penance for the delay, Cholkar gave up eating sugar. When he finally reached Shirdi and fulfilled his vow, Baba demonstrated his omniscience by telling a host to give Cholkar tea that was 'well-filled with sugar.' This act confirmed for Cholkar that Baba knew of his secret sacrifice, thereby solidifying his faith.