public function getFileContents() : string
    {
        // No point in continuing if there is no file assigned to this frame.
        if (!$this->file || $this->file === 'Unknown') {
            return '';
        }

        // If the contents aren't cached yet, grab them into our rudimentary in-memory cache.
        // Note: This may cache a boolean false if the retrieval fails for whatever reason. We're gonna handle
        // that afterwards and return an empty string instead.
        if (!isset(static::$files[$this->file])) {
            static::$files[$this->file] = file_get_contents($this->file);
        }

        // Return the cached contents of the file or an empty string if no contents could be fetched.
        return static::$files[$this->file] ?: '';
    }