@Override
  protected boolean isReusable(Bitmap value) {
    Preconditions.checkNotNull(value);
    return !value.isRecycled() && value.isMutable();
  }
Determine if this bitmap is reusable (i.e.) if subsequent {@link #get(int)} requests can use
this value. The bitmap is reusable if - it has not already been recycled AND - it is mutable

@param value the value to test for reusability
@return true, if the bitmap can be reused
imagepipeline/src/main/java/com/facebook/imagepipeline/memory/BucketsBitmapPool.java