Could you provide a summary of the story of Cholkar and his vow to Sai Baba?

The story of Cholkar, as detailed in Chapter 15, is about a man from a poor household who needed to pass an examination to secure his job. He made a vow to Sai Baba that if he passed, he would distribute sugar candy in Baba's name. Although his wish was granted and he passed the exam, he faced financial difficulties which delayed his trip to Shirdi to fulfill the vow. During this time, Cholkar gave up sugar entirely, even in his tea. When he finally managed to visit Shirdi and fulfilled his vow, Baba surprised him by telling a host to give Cholkar "cups of tea, well-filled with sugar." This act revealed Baba's omniscience, showing Cholkar that his secret penance and devotion were known, which filled Cholkar with blissful joy.