I'm trying to return a mutable Sequence with an until loop, but i have an immutable seq in return of (0 until nbGenomes) : 

```
 def generateRandomGenome(nbGenomes:Int): IndexedSeq[GenomeDouble]={
    return ((0 until nbGenomes toSeq).map{e => generateRandomGenome}) 
  }

```

Return compilation error :

```
found   : scala.collection.immutable.IndexedSeq[org.openmole.tools.mgo.mappedgenome.genomedouble.GenomeDouble]
 required: scala.collection.mutable.IndexedSeq[org.openmole.tools.mgo.mappedgenome.genomedouble.GenomeDouble]
    return ((0 until nbGenomes toSeq).map{e => generateRandomGenome}) 

```

How i can force the until loop to return an mutable seq ?
Thanks scala community!