wp-content/themes/twentyfifteen/inc/template-tags.php:282Displays the optional custom logo.
function twentyfifteen_the_custom_logo() { if ( function_exists( 'the_custom_logo' ) ) { the_custom_logo(); } }Introduced in Twenty Fifteen 1.5. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-content/themes/twentyfifteen/inc/template-tags.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.