Some of the system tests check the memory leak using a loop and multiple calls to System.gc() method. These tests can be made more robust by using JMemoryBuddy utility.
E.g.
TabPaneHeaderLeakTest
AccordionTitlePaneLeakTest
ShapeViewOrderLeakTest
SwingNodeMemoryLeakTest
SwingNodeDnDMemoryLeakTest



For reference - systems test that already use JMemoryBuddy utility:
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ViewPainterLeakTest
PlatformStartupMemoryLeakTest
VirtualFlowMemoryLeakTest
StyleMemoryLeakTest
InitialNodesMemoryLeakTest
ProgressIndicatorLeakTest