thats what i found at 213:

$value = call_user_func_array($the_[‘function’], array_slice($args, 1, (int) $the_[‘accepted_args’]));

the whole thing:

do {
foreach( (array) current($wp_filter[$tag]) as $the_ )
if ( !is_null($the_[‘function’]) ){
$args[1] = $value;
$value = call_user_func_array($the_[‘function’], array_slice($args, 1, (int) $the_[‘accepted_args’]));
}

} while ( next($wp_filter[$tag]) !== false );

array_pop( $wp_current_filter );

return $value;
}