Как работают InteropPermission и fileIOPermission?

[Lihgt]

#define.maxPath(260)
public server static str getTempPath(boolean _setPermission = true)
{
    FileIOPermission fileIOPerm;
    InteropPermission interopPerm;
    str tempPath;
    Set                 permissionSet;
    ;
    permissionSet = new Set(Types::Class);
    if(_setPermission)
    {
         // check file I/O permission
        permissionSet.add( new FileIOPermission('','r'));
        //fileIOPerm = new FileIOPermission('','r');
        //fileIOPerm.demand();
    }

    // get dll interop permission
     permissionSet.add(new InteropPermission(InteropKind::ClrInterop));
    //interopPerm = new InteropPermission(InteropKind::ClrInterop);
    //interopPerm.assert();

    CodeAccessPermission::assertMultiple(permissionSet);

    tempPath = System.IO.Path::GetTempPath();
    return tempPath;
}