Create the single outstanding changeset for staging mempool additions and removals.
Declared in <txmempool.h>
[[requires_capability(0x7fd7537baee8), requires_capability(0x7fd74eec7878), requires_capability(0x7fd75e708ec8), requires_capability(0x7fd759895698), requires_capability(0x7fd75ce07668), requires_capability(0x7fd759f70af8), requires_capability(0x7fd75b830d38), requires_capability(0x7fd73e8aef98)]]
std::unique_ptr<ChangeSet>
GetChangeSet();A new changeset bound to this mempool.