public void addDataset(int index, InvDatasetImpl ds) {
    if (ds == null) return;
    ds.setParent(this);
    datasets.add(index, ds);
    hashCode = 0;
  }
public void addDataset(int index, InvDatasetImpl ds) {
    if (ds == null) return;
    ds.setParent(this);
    datasets.add(index, ds);
    hashCode = 0;
  }
public void addDataset ( int index , InvDatasetImpl ds ) { if ( ds == null ) return ; ds . setParent ( this ) ; datasets . add ( index , ds ) ; hashCode = 0 ; }
Add a nested dataset at the location indicated by index.

@param index add at this position
@param ds    add this
Add a nested dataset at the location indicated by index .