This test checks for labels of ammonium data nodes which can use Unicode.
For a ammonium data node the label NH4+ is used, but the chemically more correct Unicode version NH₄⁺ can be used.
Open the pathway and replace the NH4+ label with a NH₄⁺ label.
IMPORTANT: PathVisio 3.3 currently does not display Unicode characters correctly in the main view, but it can still be used to edit the labels. After uploading, the classic and the new website will display the Unicode label correctly.