Skip to consider Symbol element directly, because it is calculated through...

Skip to consider Symbol element directly, because it is calculated through reference from use element

Source/SvgElement.cs

@@ -745,6 +745,12 @@ namespace Svg
         {
         	foreach(var child in elem.Children)
         	{
+            // Skip to avoid double calculate Symbol element
+            // symbol element is only referenced by use element 
+            // So here we need to skip when it is directly considered
+            if (child is Svg.Document_Structure.SvgSymbol)
+              continue;
+
         		if (child is SvgVisualElement)
         		{
         			if(!(child is SvgGroup))