if there are only Speakers all named exactly the same (at least 2), the sorting fails with
Caused by GroovyCastException: Cannot cast object 'null' with class 'null' to class 'int'. Try 'java.lang.Integer' instead
->> 324 | countRunAndMakeAscending in java.util.TimSort
| 189 | sort in ''
| 173 | sort . . in ''
| 659 | sort in java.util.Arrays
| 217 | sort . . in java.util.Collections
if there are only Speakers all named exactly the same (at least 2), the sorting fails with
Caused by GroovyCastException: Cannot cast object 'null' with class 'null' to class 'int'. Try 'java.lang.Integer' instead ->> 324 | countRunAndMakeAscending in java.util.TimSort
| 189 | sort in '' | 173 | sort . . in '' | 659 | sort in java.util.Arrays | 217 | sort . . in java.util.Collections