public Builder setDiskCachePolicy(DiskCachePolicy policy) {
      // save a member variable on the Builder so we can check it without having to hit the main thread for view access
      mDiskCachePolicy = mTileView.mDiskCachePolicy = policy;
      return this;
    }
@return True if the single ready pass executes, false otherwise (either because not ready, or already run)
tileview/src/main/java/com/moagrius/tileview/TileView.java