public Set<Value> mayAliases(Value v,Unit u){
  Set<Value> res=new HashSet<Value>();
  Set<Set<Value>> flow=getFlowBefore(u);
  for (  Set<Value> set : flow) {
    if (set.contains(v))     res.addAll(set);
  }
  return res;
}

public Set < Value > mayAliases ( Value v , Unit u ) { Set < Value > res = new HashSet < Value > ( ) ; Set < Set < Value > > flow = getFlowBefore ( u ) ; for ( Set < Value > set : flow ) { if ( set . contains ( v ) ) res . addAll ( set ) ; } return res ; }
returns all values that may - alias with v before u .
