code: func WithProcessCacheData(c context.Context, data *ProcessCacheData) context.Context {
  	if data.caches == nil {
  		panic("use NewProcessCacheData to allocate ProcessCacheData")
  	}
  	return context.WithValue(c, &processCacheKey, data)
  }
docs: // WithProcessCacheData installs an existing process-global cache storage into
  // the supplied context.
  //
  // It must be allocated via NewProcessCacheData().