isPieceFlushed
True if piece is fully written to disk (is_piece_flushed). In this core a piece is "flushed" exactly when havePiece flips it on via markAsFinished of the last block or an explicit pieceFlushed.
True if piece is fully written to disk (is_piece_flushed). In this core a piece is "flushed" exactly when havePiece flips it on via markAsFinished of the last block or an explicit pieceFlushed.