When submitting/creating a custom timer job in SharePoint, how is the job's ID set?

Question

I have a number of custom jobs that my program adds to my SharePoint environment. I noticed that there is no option to give the job a particular ID/GUID in the constructor. So my question is: How is new job's GUID/ID assigned when created and submitted?

I'm aware that I can access and modify that member of the SPJobDefinition, but I'm curious how it's set otherwise.

Answer 1

When the instance of job definition is created it ID property is initialized via base SPPersistedObject constructor to Guid.NewGuid() :

protected SPPersistedObject(string name, SPPersistedObject parent)
  : this(name, parent, Guid.NewGuid())
{
}