Coseva\CSV::_resolveFilename PHP Method

    private function _resolveFilename(&$filename, $use_include_path = false)
    {
        $exists = file_exists($filename);
        // The given filename did not suffice. Let's do a deeper check.
        if (!$exists && $use_include_path && substr($filename, 0, 1) !== '/') {
            // Gather the include paths.
            $paths = explode(':', get_include_path());
            // Walk through the include paths.
            foreach ($paths as $path) {
                // Check if the file exists within this path.
                $exists = realpath($path . '/' . $filename);
                // It didn't work. Move along.
                if (!$exists) {
                    continue;
                }
                // It actually did work. Now overwrite my filename.
                $filename = $exists;
                $exists = true;
                break;
            }
        }
        return $exists && is_readable($filename);
    }