public static IAsyncQueryable <TResult> Join <TOuter, TInner, TKey, TResult>(this IAsyncQueryable <TOuter> outer, IAsyncQueryable <TInner> inner, Expression <Func <TOuter, TKey> > outerKeySelector, Expression <Func <TInner, TKey> > innerKeySelector, Expression <Func <TOuter, TInner, TResult> > resultSelector)
{
return(Join(outer, inner.AsQueryable(), outerKeySelector, innerKeySelector, resultSelector));
}