Portfolio# struct Portfolio# Portfolio. Public Members std::string_view user# User (optional) uint32_t strategy_id = {}# Strategy identifier (optional) std::string_view account# Account name. std::span<Position const> positions# Position updates. UpdateType update_type = {}# Update type. std::chrono::nanoseconds exchange_time_utc = {}# Exchange timestamp, possibly from matching engine (UTC) UUID session_id# Reference (UUID) uint64_t seqno = {}# Reference (sequencing)