Learn ABAP using samples: Class CVI_KA_BP_CUSTOMER

Class name CVI_KA_BP_CUSTOMER (by components: CVI-KA-BP-CUSTOMER)  Assignment of BP to Customer 

Interface IF_UKM_EASY with methods:

• Addition of key mappings
• Query of key mappings
• Deletion of key mappings
• Transfer to the posting module
• Reset of internal buffer

Superclass AC_CVI_KEY_ASSIGNMENT implements the interface IF_UKM_EASY + declares new methods. And the class is used for  CVI_KA_BP_CUSTOMER.

In addition, one more interface IF_CVI_COMMON_CONSTANTS is used just for constants. 

Attributes of the class:

• Constants from the interface 
• Assignments (tables); all, to create and delete 

Methods ( to manage assignments ):

• get_instance
• if instance is not bound.
• create object instance.
• endif.
• r_instance = instance.
• factory is to call get_instance
• new_assignment .. contains already restriction for the number of lines
• various methods to get the customizing .. one table - one method 
• IS_ methods are boolean
• CHECK_ methods return error table ( codes )
• GET_ methods are return data tables 
• flush operation is run via update task 
• each method has clear test description

Most methods are instance methods.

The CVI classes have complex logic and it is not filled with comments to have clear understanding at a glance. How this code is supported. Do they have own technical documentation besides UML diagrams ?