<PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="7.0.0-preview.7.22375.6" />

MemberNotNullAttribute

Specifies that the method or property will ensure that the listed field and property members have not-null values.
public string[] Members { get; }

Gets field or property member names.

public MemberNotNullAttribute(string member)

Initializes the attribute with a field or property member.

public MemberNotNullAttribute(string[] members)

Initializes the attribute with the list of field and property members.