Implicit foreach:
int(1)
#0  gen() called at [/home/kienthuc1/tool.kienthuclinux.info/services/custombuild/php/php-8.3.6/Zend/tests/generators/yield_from_backtrace.php:16]
int(2)
#0  from(2) called at [/home/kienthuc1/tool.kienthuclinux.info/services/custombuild/php/php-8.3.6/Zend/tests/generators/yield_from_backtrace.php:11]
#1  gen() called at [/home/kienthuc1/tool.kienthuclinux.info/services/custombuild/php/php-8.3.6/Zend/tests/generators/yield_from_backtrace.php:16]
int(3)
#0  gen() called at [/home/kienthuc1/tool.kienthuclinux.info/services/custombuild/php/php-8.3.6/Zend/tests/generators/yield_from_backtrace.php:16]

Explicit iterator:
int(1)
#0  gen()
#1  Generator->next() called at [/home/kienthuc1/tool.kienthuclinux.info/services/custombuild/php/php-8.3.6/Zend/tests/generators/yield_from_backtrace.php:21]
int(2)
#0  from(2) called at [/home/kienthuc1/tool.kienthuclinux.info/services/custombuild/php/php-8.3.6/Zend/tests/generators/yield_from_backtrace.php:11]
#1  gen()
#2  Generator->next() called at [/home/kienthuc1/tool.kienthuclinux.info/services/custombuild/php/php-8.3.6/Zend/tests/generators/yield_from_backtrace.php:21]
int(3)
#0  gen()
#1  Generator->next() called at [/home/kienthuc1/tool.kienthuclinux.info/services/custombuild/php/php-8.3.6/Zend/tests/generators/yield_from_backtrace.php:21]