Function trace_num 

pub unsafe extern "C" fn trace_num(
    read_ptr: u32,
    read_len: u32,
    number: i64,
) -> i64

Print some output to the trace log on xrpld along with a decimal number. Any xrpld instance set to “trace” log level will see this. @param read_ptr A pointer to the string to output @param read_len The length of the string to output @param number Any integer you wish to display after the text @return A negative value on error