Function decode_instrument_def_msg 

pub fn decode_instrument_def_msg(
    msg: &InstrumentDefMsg,
    instrument_id: InstrumentId,
    ts_init: Option<UnixNanos>,
    decode_config: Option<&DatabentoDecodeConfig>,
) -> Result<Option<InstrumentAny>>

Errors

Returns an error if decoding the InstrumentDefMsg fails.

Returns Ok(None) for instrument classes with no Nautilus equivalent ('I' Index, 'B' Bond, or any future class) and FX spots that cannot be mapped to known currencies.