Reintroduce erroneously deleted `description` method and relative test in MultisetPrintableTests
Reintroduce erroneously deleted `description` method and relative test in MultisetPrintableTests

robrix/Set,madbat/Set,madbat/Set,natecook1000/Set,madbat/Set,robrix/Set,robrix/Set,natecook1000/Set,natecook1000/Set