wp-includes/rest-api/class-wp-rest-request.php:562Sets parameters from the body.
$paramsarray public function set_body_params( $params ) { $this->params['POST'] = $params; }Introduced in 4.4.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/rest-api/class-wp-rest-request.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.