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

NullableCallLiftKind

namespace Microsoft.CSharp.RuntimeBinder.Semantics { internal enum NullableCallLiftKind { NotLifted, Operator, EqualityOperator, InequalityOperator, UserDefinedConversion, NullableConversion, NullableConversionConstructor, NullableIntermediateConversion, NotLiftedIntermediateConversion } }