void GroupScopeClose(GroupScope scope)
{
scope.OnDisposed -= GroupScopeClose;
if (_groupStack.Pop() != scope.Group)
{
throw new System.Exception("Unexpected group was closed.");
}
}
protected GroupScope Group(OutputGroup group)
{
var scope = new GroupScope(group);
scope.OnDisposed += GroupScopeClose;
_groupStack.Push(scope.Group);
return(scope);
}