Android Question PDFium_OnTap

[RB Smissaert]

Tried the PDFium demo app and all working OK, except there was an error on tapping the screen:
java.lang.Exception: Sub pdfium_ontap was not found.

Couldn't find anywhere what the arguments for this Sub should be, but managed to avoid the error with this Sub:

Sub PDFium_OnTap(o As Object)
    Log("PDFium_OnTap")
End Sub

What is the object passed to this Sub and how could it be used?

RBS