How to programmatically check if a service is declared in AndroidManifest.xml?

I'm writing a library that provides a Service that is used by other developers by including it in their project. As such, I don't have control over the AndroidManifest.xml. I explain what to do in the docs, but nevertheless a common problem is that people neglect to add the appropriate <service/> tag to their manifest, or add it in the wrong place.

Right now, when my library calls startService while the service isn't declared in the manifest, the only thing that happens is that ActivityManager logs a warning. I would like to throw an exception when this happens so that developers know how to fix it. How can I detect whether the manifest actually declares this Service?