if (sr_dev->config_check(ConfigKey::EXTERNAL_CLOCK, Capability::GET)) {
try {
auto gvar = sr_dev->config_get(ConfigKey::EXTERNAL_CLOCK);
if (sr_dev->config_check(ConfigKey::EXTERNAL_CLOCK, Capability::GET)) {
try {
auto gvar = sr_dev->config_get(ConfigKey::EXTERNAL_CLOCK);