Public Overridable Function onGetFilter( _
   ByRef _eventType As Integer, _
   ByRef numCategories As Integer, _
   ByRef eventCategories As Integer(), _
   ByRef lowSeverity As Integer, _
   ByRef highSeverity As Integer, _
   ByRef numAreas As Integer, _
   ByRef areaList As String(), _
   ByRef numSources As Integer, _
   ByRef sourceList As String() _
) As Integer

public virtual int onGetFilter( 
   out int _eventType,
   out int numCategories,
   out int[] eventCategories,
   out int lowSeverity,
   out int highSeverity,
   out int numAreas,
   out string[] areaList,
   out int numSources,
   out string[] sourceList
)