Optionalarg1: anyFirst argument that is passed from caller.
Optionalarg2: anySecond argument that is passed from caller.
Optionalarg3: anyThird argument that is passed from caller.
Optionalarg4: anyFourth argument that is passed from caller.
Optionalarg5: anyFifth argument that is passed from caller.
Optionalarg6: anySixth argument that is passed from caller.
Optionalarg7: anySeventh argument that is passed from caller.
Optionalarg8: anyEighth argument that is passed from caller.
Callback used by EventHandler functions. Note the callback is limited to 8 arguments.