UrlToQueryItem.php
private function parsePrivateQueryVars( Array $extra = [ ], Array $private = [ ] ) {
        if ( ! empty( $extra ) ) {
            foreach ( $private as $var ) {
                if ( isset( $extra[$var] ) ) {
                    $this->query_vars[$var] = $extra[$var];
                }
            }
        }
    }
private function parsePrivateQueryVars( Array $extra = [ ], Array $private = [ ] ) {
        if ( ! empty( $extra ) ) {
            foreach ( $private as $var ) {
                if ( isset( $extra[$var] ) ) {
                    $this->query_vars[$var] = $extra[$var];
                }
            }
        }
    }
private function parsePrivateQueryVars ( Array $ extra = [ ] , Array $ private = [ ] ) { if ( ! empty ( $ extra ) ) { foreach ( $ private as $ var ) { if ( isset ( $ extra [ $ var ] ) ) { $ this -> query_vars [ $ var ] = $ extra [ $ var ] ; } } } }
Look in extra query variables passed to resolver and compare to WP object private variables
if some variables are found they are added to query variables to be returned

@param array $extra
@param array $private
Look in extra query variables passed to resolver and compare to WP object private variables if some variables are found they are added to query variables to be returned