@Nonnull
	private static KtFunction mapFunction(@Nonnull MetadataNameResolver res, @Nonnull ProtoBuf.Function function) {
		String name = function.hasName() ? res.resolve(function.getName()) : null;
		KtType returnType = function.hasReturnType() ? mapType(res, function.getReturnType()) : null;
		List<KtVariable> parameters = function.getValueParameterList().stream().map(vp -> mapParameter(res, vp)).toList();
		return new KtFunction(name, returnType, parameters);
	}
@param visitor
		Visitor of a kotlin class with a {@code @Metadata} annotation to extract information from.

@return Extracted class model from the {@code @Metadata} or {@code null} if no annotation was found.
recaf-core/src/main/java/software/coley/recaf/util/kotlin/KotlinMetadata.java