Public Class C

    Dim a, b As New C((Function(n) n + 1)(1))

    Sub New(a As Integer) : End Sub
End Class

System.ArgumentException: An item with the same key has already been added. Key: Private Function (n As Object) As Object
   at System.Collections.Generic.Dictionary`2.TryInsert(TKey key, TValue value, InsertionBehavior behavior)
   at Microsoft.CodeAnalysis.VisualBasic.LambdaRewriter.Analysis.VisitLambda(BoundLambda node, Boolean convertToExpressionTree)
   at Microsoft.CodeAnalysis.VisualBasic.LambdaRewriter.Analysis.VisitConversion(BoundConversion conversion)
   at Microsoft.CodeAnalysis.VisualBasic.BoundConversion.Accept(BoundTreeVisitor visitor)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32& recursionDepth, BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.Visit(BoundNode node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitCall(BoundCall node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundCall.Accept(BoundTreeVisitor visitor)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32& recursionDepth, BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.Visit(BoundNode node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitList[T](ImmutableArray`1 list)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitCall(BoundCall node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundCall.Accept(BoundTreeVisitor visitor)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32& recursionDepth, BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.Visit(BoundNode node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitList[T](ImmutableArray`1 list)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitObjectCreationExpression(BoundObjectCreationExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundObjectCreationExpression.Accept(BoundTreeVisitor visitor)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32& recursionDepth, BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.Visit(BoundNode node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitAssignmentOperator(BoundAssignmentOperator node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundAssignmentOperator.Accept(BoundTreeVisitor visitor)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeVisitor.VisitExpressionWithStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32& recursionDepth, BoundExpression node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.Visit(BoundNode node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitExpressionStatement(BoundExpressionStatement node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundExpressionStatement.Accept(BoundTreeVisitor visitor)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.Visit(BoundNode node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitSequencePoint(BoundSequencePoint node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundSequencePoint.Accept(BoundTreeVisitor visitor)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.Visit(BoundNode node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitList[T](ImmutableArray`1 list)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitStatementList(BoundStatementList node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundStatementList.Accept(BoundTreeVisitor visitor)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.Visit(BoundNode node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitList[T](ImmutableArray`1 list)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalker.VisitBlock(BoundBlock node)
   at Microsoft.CodeAnalysis.VisualBasic.LambdaRewriter.Analysis.VisitBlock(BoundBlock node)
   at Microsoft.CodeAnalysis.VisualBasic.BoundBlock.Accept(BoundTreeVisitor visitor)
   at Microsoft.CodeAnalysis.VisualBasic.BoundTreeWalkerWithStackGuard.Visit(BoundNode node)
   at Microsoft.CodeAnalysis.VisualBasic.LambdaRewriter.Analysis.Analyze(BoundNode node)