Intent of executionGraph.ts ×2

All 4 exact tests in this concept. Every test is marked by where it enters the hierarchy.

mocha:v1|namespace=vscode@05c208e9e28d8c1c723fa08f85e2b7a96092e8e5|file=vs/ 4 tests
- base/ 4 tests
  - test/ 4 tests
    
    common/ 4 tests
    
    mocha:v1|namespace=vscode@05c208e9e28d8c1c723fa08f85e2b7a96092e8e5|file=vs/base/test/common/executionGraph.test|title=executionGraph renderSwimlanes: degenerate linked-list tree (5 nodes)|occurrence=1 Inherited executionGraph.ts ×5
    
    mocha:v1|namespace=vscode@05c208e9e28d8c1c723fa08f85e2b7a96092e8e5|file=vs/base/test/common/executionGraph.test|title=executionGraph renderSwimlanes: empty history|occurrence=1 Introduced here
    
    mocha:v1|namespace=vscode@05c208e9e28d8c1c723fa08f85e2b7a96092e8e5|file=vs/base/test/common/executionGraph.test|title=executionGraph renderSwimlanes: forest with forks across two roots|occurrence=1 Inherited executionGraph.ts ×1
    
    mocha:v1|namespace=vscode@05c208e9e28d8c1c723fa08f85e2b7a96092e8e5|file=vs/base/test/common/executionGraph.test|title=executionGraph renderSwimlanes: single root, linear chain|occurrence=1 Inherited executionGraph.ts ×5