 
     public static func open(container data: Data) throws -> [ContainerEntry] {
         var entries = [SevenZipEntry]()
-        let header = try readHeader(data)
+        guard let header = try readHeader(data)
+            else { return [] }
 
         guard let files = header.fileInfo?.files
             else { return [] }

        bitReader.index += nextHeaderOffset
        let headerStartIndex = bitReader.index
        let headerEndIndex: Int

        let type = bitReader.byte()
        let header: SevenZipHeader


    public static func info(container data: Data) throws -> [SevenZipEntryInfo] {
        var entryInfos = [SevenZipEntryInfo]()
        guard let header = try readHeader(data)
            else { return [] }

        guard let files = header.fileInfo?.files
            else { return [] }
