core-bundle/src/EventListener/GlobalsMapListener.php
public function onInitializeSystem(): void
    {
        foreach ($this->globals as $key => $value) {
            if (\is_array($value) && isset($GLOBALS[$key]) && \is_array($GLOBALS[$key])) {
                $GLOBALS[$key] = array_replace_recursive($GLOBALS[$key], $value);
            } else {
                $GLOBALS[$key] = $value;
            }
        }
    }
public function onInitializeSystem(): void
    {
        foreach ($this->globals as $key => $value) {
            if (\is_array($value) && isset($GLOBALS[$key]) && \is_array($GLOBALS[$key])) {
                $GLOBALS[$key] = array_replace_recursive($GLOBALS[$key], $value);
            } else {
                $GLOBALS[$key] = $value;
            }
        }
    }
Maps fragments to the globals array.