protected:
bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const;
bool lessThan(const QModelIndex &source_left, const QModelIndex &source_right) const;
bool bufferLessThan(const QModelIndex &source_left, const QModelIndex &source_right) const;
bool networkLessThan(const QModelIndex &source_left, const QModelIndex &source_right) const;
protected:
bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const;
bool lessThan(const QModelIndex &source_left, const QModelIndex &source_right) const;
bool bufferLessThan(const QModelIndex &source_left, const QModelIndex &source_right) const;
bool networkLessThan(const QModelIndex &source_left, const QModelIndex &source_right) const;