How do I retrieve a custom property from a Microsoft.SharePoint.Client.Folder?

Greets,

I have a reference to a Microsoft.SharePoint.Client.Folder object:

Folder folder = _libraryClientContent.Web.GetFolderByServerRelativeUrl(PATH_DEV_DOWNLOAD + GetDirectoryNameFromPathSP(filename));

The folder MAY contain a custom property. How can I determine:

1. if this property exists on the folder


2. retrieve the property value if it exists?

Requirements:

• Works in SharePoint 2010 environment


• C# (or easily convertible)


• Uses all standard SharePoint resources; no add-ons, no GitHub, no CodePlex

I have a solution that works but takes way too much time. I need something small and fast.

Thanks in advance for your assistance!