# start the B3 instance and sleep a bit: give it time to crash (if that's the case).
    # recompute also the PID file path because $(b3_pid_path) may output an empty string
    # if the B3 was not running (and thus no PID file could be found in previous call)
    local SCREEN="${COMMON_PREFIX}${B3}"
    local PROCESS="$(readlink -f "${B3_RUN}")"
    local PID_FILE="$(readlink -f "${PID_PATH}/${COMMON_PREFIX}${B3}${PID_EXT}")"

    if [ ${AUTO_RESTART} -eq 1 ]; then
        screen -DmS "${SCREEN}" python "${PROCESS}" --restart --config "${CONFIG_FILE}" &
    else
        screen -DmS "${SCREEN}" python "${PROCESS}" --config "${CONFIG_FILE}" &
    fi

    echo "${!}" > "${PID_FILE}"

    if [ ${AUTO_RESTART} -eq 1 ]; then
        sleep 4
    else
        sleep 1
    fi