inverse(forRelationshipKey:)

The name of the inverse relationship from the relationship specified by relationshipKey.

For a given key that defines the name of the relationship from the receiver’s class to another class, returns the name of the relationship from the other class to the receiver’s class. For example, suppose an Employee class has a relationship named department to a Department class, and that Department has a relationship named employees to Employee. The statement:

[employee inverseForRelationshipKey:@"department"];

returns the string employees.

If you have an instance of the class the receiver describes, you can use the NSObject instance method inverse(forRelationshipKey:) instead.