Create the single outstanding changeset for staging mempool additions and removals.
Declared in <txmempool.h>
[[requires_capability(0x7fbc8f6855e8), requires_capability(0x7fbc95d47348), requires_capability(0x7fbca708d008), requires_capability(0x7fbc862758a8), requires_capability(0x7fbca7899f88), requires_capability(0x7fbc84abb5d8), requires_capability(0x7fbc870faad8), requires_capability(0x7fbc921e2398)]]
std::unique_ptr<ChangeSet>
GetChangeSet();A new changeset bound to this mempool.