Can you tell me the full story of Cholkar's vow to Sai Baba and how it was fulfilled?

The story of Cholkar, as told in Chapter 15, is one of faith and Sai Baba's omniscience. Cholkar was a poor man whose livelihood depended on passing an examination to make his job permanent. He made a vow to Baba that if he passed, he would come for darshan and distribute sugar candy. By Baba's grace, his wish was granted. However, due to his financial struggles, described as the difficult 'threshold-ghat' of home expenses, he could not immediately afford the trip to Shirdi. As a personal penance for this delay, he gave up eating sugar. When he finally managed to visit Shirdi, he fulfilled his vow by distributing sugar. The climax of the story occurs when Baba, who did not drink tea, instructs a host to give Cholkar 'cups of tea, well-filled with sugar.' This act revealed to Cholkar that Baba was aware of his secret sacrifice all along, filling him with joyful tears.