public function getRevision($revision)
	{
		// Select revision by index
		if (is_int($revision)) {
			if (isset($this->history[$revision])) {
				return $this->history[$revision];
			}
		// Search revision by timestamp
		} else {
			foreach ($this->history as $history) {
				if ($history['timestamp'] == $revision) {
					return $history;
				}
			}
		}

		// Return error message
		$this->error = array();
		$this->error['file'] = "Revision '$revision' was not found for this file";
		return null;
	}