Why does DiagnosticAnalyzer.RegisterSymbolStartAction(...) not accept SymbolKind array?

[Denis535]

I'm learing DiagnosticAnalyzer and I wonder one thing: why does RegisterSymbolStartAction not accept SymbolKind array but RegisterSymbolAction does?

What if I want to subscribe to SymbolKind.NamedType, SymbolKind.Field, SymbolKind.Property, SymbolKind.Method events? Now I'm forced to write RegisterSymbolStartAction for each SymbolKind.

context.RegisterSymbolStartAction( OnSymbol_Start, SymbolKind.NamedType );
context.RegisterSymbolStartAction( OnSymbol_Start, SymbolKind.Field );
context.RegisterSymbolStartAction( OnSymbol_Start, SymbolKind.Property );
context.RegisterSymbolStartAction( OnSymbol_Start, SymbolKind.Method );
context.RegisterSymbolAction( OnSymbol, SymbolKind.NamedType, SymbolKind.Field, SymbolKind.Property, SymbolKind.Method );

This is probably the dumbest question but I I really wonder :)

I can assume that this is because SymbolKind.NamedType is parent syntax node and it's enough to process all child nodes.
But what if I want to process only some child nodes?