CopyTo error after conversion from C# to VB.NET

So I converted a code from C# about Unziping a file using WindowsBase DLL:

  public void UnZip(string pathToZipFile, string destinationPath)
        {
            try
            {
                using (Package package = ZipPackage.Open(pathToZipFile, FileMode.Open, FileAccess.Read))
                {
                    foreach (PackagePart part in package.GetParts())
                    {
                        var target = Path.GetFullPath(Path.Combine(destinationPath, part.Uri.OriginalString.TrimStart('/')));
                        var targetDir = target.Remove(target.LastIndexOf('\\'));
                        if (!Directory.Exists(targetDir))
                            Directory.CreateDirectory(targetDir);
                        using (Stream source = part.GetStream(FileMode.Open, FileAccess.Read))
                        {
                            source.CopyTo(File.OpenWrite(target));
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message + " (Event: UnZip)");
            }
        }

    Public Sub UnZip(ByVal pathToZipFile As String, ByVal destinationPath As String)
        Try
            Using package As Package = ZipPackage.Open(pathToZipFile, FileMode.Open, FileAccess.Read)
                For Each part As PackagePart In package.GetParts()
                    Dim target = Path.GetFullPath(Path.Combine(destinationPath, part.Uri.OriginalString.TrimStart("/"c)))
                    Dim targetDir = target.Remove(target.LastIndexOf("\"c))

                    If Not Directory.Exists(targetDir) Then
                        Directory.CreateDirectory(targetDir)
                    End If

                    Using source As Stream = part.GetStream(FileMode.Open, FileAccess.Read)
                        source.CopyTo(File.OpenWrite(target))
                    End Using
                Next
            End Using
        Catch ex As Exception
            Throw New Exception(ex.Message + " (Event: UnZip)")
        End Try
    End Sub

I got error "'CopyTo' is not a member of 'System.IO.Stream'.