public static TResult CachedExpression<TSource, TArg1, TResult>(
    this IQueryable<TSource> source,
    Func<IQueryable<TSource>, TArg1, TResult> f,
    TArg1 a1
)

<ExtensionAttribute>
Public Shared Function CachedExpression(Of TSource, TArg1, TResult)(
    source As IQueryable(Of TSource),
    f As Func(Of IQueryable(Of TSource), TArg1, TResult),
    a1 As TArg1
) As TResult