The admin user who filled the swap by hand; null on an automatic fill.
The CFX ledger account the fill's MOVEUSD came from; null until filled.
Whether each side's address is a LEGACY_MINTFX secret's, which a swap never moves.
wallet-api's wallet for the swap's ledger account; null before ledger accounts funded swaps.
A swap as CFX reads it: its owner, and the wallet that signs as its ledger account.