Implement some simplifications in the data model

[amolenaar]

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Documentation content changes

What is the current behavior?

There is some complexity in the data model that I like to get rid of.

What is the new behavior?

Slightly cleaner code.

Does this PR introduce a breaking change?

• Yes
• No -- not for the user

[sourcery-ai]

Sourcery Code Quality Report (beta)

Merging this PR leaves code quality unchanged.

Quality metrics	Before	After	Change
Complexity	2.02	2.01	-0.01 🔵
Method Length	76.20	75.66	-0.54 🔵
Quality	8.66	8.66	0.00

Other metrics	Before	After	Change
Lines	4501	4419	-82

Changed files	Quality Before	Quality After	Quality Change
gaphor/SysML/sysml.py	5.06	5.06	0.00
gaphor/UML/uml.py	4.90	4.90	0.00
gaphor/UML/umloverrides.py	9.20	9.21	0.01 🔵
gaphor/codegen/profile_coder.py	7.74	7.72	-0.02 🔴
gaphor/codegen/writer.py	7.51	7.55	0.04 🔵
gaphor/codegen/tests/test_uml_coder.py	9.36	9.36	0.00
gaphor/core/modeling/coremodel.py	8.86	8.87	0.01 🔵
gaphor/core/modeling/properties.py	9.05	9.06	0.01 🔵
gaphor/core/modeling/tests/test_properties.py	8.09	8.10	0.01 🔵
gaphor/services/tests/test_undomanager.py	8.06	8.06	0.00

Here are some functions in these files that still need a tune-up:

File	Function	Complexity	Length	Overall	Recommendation
gaphor/core/modeling/properties.py	derivedunion.propagate	35	212.95	3.04	Reduce complexity. Split out functionality
gaphor/codegen/profile_coder.py	write_properties	36	202.66	3.08	Reduce complexity. Split out functionality
gaphor/codegen/writer.py	Writer.add_attribute	17	235.61	4.23	Split out functionality
gaphor/codegen/writer.py	Writer.add_derivedunion	18	169.74	4.82	Split out functionality
gaphor/core/modeling/tests/test_properties.py	test_association_1_n	2	255.79	5.52	Split out functionality

Please see our documentation here for details on how these metrics are calculated.

We are actively working on this report - lots more documentation and extra metrics to come!

Let us know what you think of it by mentioning @sourcery-ai in a comment.

[danyeaw]

Nice updates!