public function add($prefix, $paths, $prepend = false) {
		if (!$prefix) {
			if ($prepend) {
				$this->fallbackDirs = array_merge(
					(array) $paths,
					$this->fallbackDirs
				);
			}
			else {
				$this->fallbackDirs = array_merge(
					$this->fallbackDirs,
					(array) $paths
				);
			}

			return;
		}

		if (!isset($this->prefixes[$prefix])) {
			$this->prefixes[$prefix] = (array) $paths;
			return;
		}

		if ($prepend) {
			$this->prefixes[$prefix] = array_merge(
				(array) $paths,
				$this->prefixes[$prefix]
			);
		}
		else {
			$this->prefixes[$prefix] = array_merge(
				$this->prefixes[$prefix],
				(array) $paths
			);
		}
	}