Create Passive Sell Offer Op Xdr
data class CreatePassiveSellOfferOpXdr(val selling: AssetXdr, val buying: AssetXdr, val amount: Int64Xdr, val price: PriceXdr)
XDR Source: struct CreatePassiveSellOfferOp { Asset selling; // A Asset buying; // B int64 amount; // amount taker gets Price price; // cost of A in terms of B };