For some historical antecedents... Kent Beck and Erich Gamma in discussing JUnit in early 2000's proposed "pattern density" as a measure of a good object-orien

For some historical antecedents... Kent Beck and Erich Gamma in discussing JUnit in early 2000's proposed "pattern density" as a measure of a good object-oriented design. But pattern density was criticized as embrittling. Because the same component was participating in multiple patterns, the component became impossible to change. For perhaps these reasons, they removed the Composite and Command patterns from JUnit 4.