if (result instanceof IFileSystem)
return (IFileSystem) result;
try {
IConfigurationElement element = (IConfigurationElement) result;
FileSystem fs = (FileSystem) element.createExecutableExtension("run"); //$NON-NLS-1$
fs.initialize(scheme);
//store the file system instance so we don't have to keep recreating it
registry.put(scheme, fs);
return fs;
} catch (CoreException e) {
//remove this invalid file system from the registry