wp-includes/IXR/class-IXR-clientmulticall.php:50$argsbool function query( ...$args ) { // Prepare multicall, then call the parent::query() method return parent::query('system.multicall', $this->calls); }Introduced in 1.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/IXR/class-IXR-clientmulticall.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.