///
void setBufferId(int buffer_id) const { buffer_id_ = buffer_id; }
///
void setUsed(bool u) const { used_ = u; }
///
bool used() const { return used_; }
///
void setBufferId(int buffer_id) const { buffer_id_ = buffer_id; }
///
void setUsed(bool u) const { used_ = u; }
///
bool used() const { return used_; }