Block builder used to iterate mempool chunks in mining order while assembling a block.
Declared in <txmempool.h>
[[guarded_by(0x7f2e1b5a14c8), guarded_by(0x7f2e2721a4d8), guarded_by(0x7f2e421cbbe8), guarded_by(0x7f2e2880aba8), guarded_by(0x7f2e3212df38), guarded_by(0x7f2e347f65c8), guarded_by(0x7f2e2b05aa38), guarded_by(0x7f2e2bee20d8)]]
mutable
std::unique_ptr<TxGraph::BlockBuilder> m_builder;