type google.golang.org/protobuf/reflect/protoregistry.extensionsByNumber

3 uses

	google.golang.org/protobuf/reflect/protoregistry (current package)
		registry.go#L489: 	extensionsByMessage map[protoreflect.FullName]extensionsByNumber
		registry.go#L490: 	extensionsByNumber  map[protoreflect.FieldNumber]protoreflect.ExtensionType
		registry.go#L566: 		r.extensionsByMessage[message] = make(extensionsByNumber)