“cfffb1a36251e7d06535dac6db220131e36fe9f8”上不存在“paddle/phi/kernels/class_center_sample_kernel.h”
* Fix bug in MergeModel.cpp. * Add a c-api inferface to initilize the thread environment of Paddle and add a GPU example. * Add some note for paddle_init_thread and move the inplementation of paddle_error_string into a .cpp file. * Add some comments.