Please answer a question about the following article about Sino-Tibetan relations during the Ming dynasty:

Wang and Nyima state that after the official title "Education Minister" was granted to Tai Situ Changchub Gyaltsen (1302–1364) by the Yuan court, this title appeared frequently with his name in various Tibetan texts, while his Tibetan title "Degsi" (sic properly sde-srid or desi) is seldom mentioned. Wang and Nyima take this to mean that "even in the later period of the Yuan dynasty, the Yuan imperial court and the Phagmodrupa Dynasty maintained a Central-local government relation." The Tai Situpa is even supposed to have written in his will: "In the past I received loving care from the emperor in the east. If the emperor continues to care for us, please follow his edicts and the imperial envoy should be well received."

Who wrote in their will that they received loving care from the emperor in the east?
The Tai Situpa