Can you give me a full summary of Cholkar's story? What prompted him to make a vow to begin with?

The story of Cholkar, found in Chapter 15, begins with his desire to make his job permanent by passing an examination. Inspired by one of Das Ganu's kirtans, Cholkar, a man from a poor household, made a vow to Sai Baba: if he passed, he would come to Shirdi and distribute sugar candy. His wish was granted, but due to financial hardship, he couldn't immediately travel to fulfill the vow. As a penance for the delay, he gave up eating sugar. Eventually, he managed to go to Shirdi, where he fulfilled his promise. The climax occurred when Baba, who knew Cholkar's secret sacrifice, instructed that he be given tea 'well-filled with sugar,' confirming his omniscience and filling Cholkar with devotion.