What's the point of jsdebug.c?

Does anyone understand why jsdebug.c exists? It has functions like
---
  JSD_PUBLIC_API(JSBool)
  JSD_SetScriptHook(JSDContext* jsdc, JSD_ScriptHookProc hook, void* 
callerdata)
  {
      JSD_ASSERT_VALID_CONTEXT(jsdc);
      return jsd_SetScriptHook(jsdc, hook, callerdata);
  }
----
Why?

jjb