protected boolean constantZero(List<V> column,Adapter adapter){
  for (int i=0, s=adapter.size(column); i < s; i++) {
    if (adapter.get(column,i) != 0.) {
      return false;
    }
  }
  return true;
}

protected boolean constantZero ( List < V > column , Adapter adapter ) { for ( int i = 0 , s = adapter . size ( column ) ; i < s ; i ++ ) { if ( adapter . get ( column , i ) != 0. ) { return false ; } } return true ; }
test if an attribute is constant zero .
