public CharacteristicTypeSymbol(
     IProfileTypeSymbol containingSymbol,
     CharacteristicTypeNode declaration,
     DiagnosticBag diagnostics)
     : base(containingSymbol, declaration)
 {
     Declaration           = declaration;
     ContainingProfileType = containingSymbol;
 }
 public static ProfileTypeNode?GetDeclaration(this IProfileTypeSymbol symbol) =>
 GetDeclarationCore <ProfileTypeSymbol, ProfileTypeNode>(symbol);