func appendElem(symbolPath, childName string) string {
	if symbolPath == "" {
		return childName + "."
	}
	return fmt.Sprintf("%s.%s", symbolPath, childName)
}
appendEnum is a helper function for appending two symbol paths together. It's
not generic enough to be public (i.e. it can only work for the below use
cases).
package util
import (
	"fmt"
	descriptor "github.com/golang/protobuf/protoc-gen-go/descriptor"
)
func nameMessage(old *descriptor.DescriptorProto, newName string) *descriptor.DescriptorProto {
	cpy := *old
	cpy.Name = &newName
	return &cpy
}
func nameEnum(old *descriptor.EnumDescriptorProto, newName string) *descriptor.EnumDescriptorProto {
	cpy := *old
	cpy.Name = &newName
	return &cpy
}