question: private List < int [ ] > prepareExpectedData ( ) { List < int [ ] > indexList = new ArrayList < > ( 2 ) ; int [ ] sortIndex = { 0 , 3 , 2 , 4 , 1 } ; int [ ] sortIndexInverted = { 0 , 2 , 4 , 1 , 2 } ; indexList . add ( 0 , sortIndex ) ; indexList . add ( 1 , sortIndexInverted ) ; return indexList ; }
target:  Method return the list of sortIndex and sortIndexInverted array