I want to know the answer to the following question:
When did Hou Xian and Zhi Guang return to Nanjing?
All the background I'm provided with is that "In order to seek out the Karmapa, the Yongle Emperor dispatched his eunuch Hou Xian and the Buddhist monk Zhi Guang (d. 1435) to Tibet.". Is that enough to answer the question?