thrift/server.go
func (s *Server) SetContextFn(f func(ctx context.Context, method string, headers map[string]string) Context) {
	s.ctxFn = f
}
func (s *Server) SetContextFn(f func(ctx context.Context, method string, headers map[string]string) Context) {
	s.ctxFn = f
}
// SetContextFn sets the function used to convert a context.Context to a thrift.Context.
// Note: This API may change and is only intended to bridge different contexts.