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Once a model starts to become complex (see MODEL COMPLEXITY Model Complexity) and test generation time exceeds your threshold of patience, start to generate tests from subactivity diagrams, i.e., by setting a sub activity diagram to be the “main diagram” and generating tests. This technique should be used to study in particular newly added functionality in isolation before you evaluate it as part of the full model. Note that you may need to prepare the activity diagrams before using them in isolation (e.g., copy and initialize [state] variables temporarily into the isolated diagrams).
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