<PackageReference Include="Microsoft.CSharp" Version="4.7.0-preview2.19523.17" />

Microsoft.CSharp.RuntimeBinder.Semantics.EXPRUSERDEFINEDCONVERSION

namespace Microsoft.CSharp.RuntimeBinder.Semantics { internal class EXPRUSERDEFINEDCONVERSION : EXPR { public EXPR Argument; public EXPR UserDefinedCall; public MethWithInst UserDefinedCallMethod; public EXPRUSERDEFINEDCONVERSION(); } }