public virtual SymbolFilterReason GetReason(IEventSymbol symbol)
{
if (symbol.IsImplicitlyDeclared)
return SymbolFilterReason.ImplicitlyDeclared;
if (!Includes(SymbolGroupFilter.Event))
return SymbolFilterReason.SymbolGroup;
if (!symbol.IsVisible(Visibility))
return SymbolFilterReason.Visibility;
return GetRulesReason(symbol);
}