HttpContext is null

Question

I have the code below to set the HttpContext.Current. It works on Windows but in Mac I encounter the following errors:

 

'HttpContext' is a type, which is not valid in the given context

 

And a message when pointing the cursor to HttpContext

 

Inconsistent body style: use expression body

public BrandModel Brand
{
get{
return (Get<BrandModel>("Brand"));
}
set{
HttpContext.Current.Session["Brand"] = value;
}
}

What should I do?