if ( isset( self::$psr4Namespaces[$prefix] ) ) {
$relativeClass = substr( $className, $pos + 1 );
// Build the expected filename, and see if it exists
if ( isset( self::$psr4Namespaces[$prefix] ) ) {
$relativeClass = substr( $className, $pos + 1 );
// Build the expected filename, and see if it exists