How to open an existing .mom file, or is there any way to see the structure of an existing .mom file

How to open an existing .mom file, or is there any way to see the
structure of an existing .mom file

I've downloaded a copy of iOS source code and there is a .mom file in the
bundle. I just know it is a "product" of NSManagedObjectModel. I wonder is
there any way that I can explore the entities in the file, or is there any
code snippet to parse its structure. Thank you!