in src/PublicToInternalGenerator/PublicToInternalGenerator.cs [172:180]
public override SyntaxNode? VisitStructDeclaration(StructDeclarationSyntax node)
{
var visited = (StructDeclarationSyntax?)base.VisitStructDeclaration(node);
if (visited is null) return null;
visited = WithExtraAttributes(visited);
visited = ChangePublicToInternal(visited);
return visited;
}