public AllocationSite(int line,int column){
synchronized (sites) {
    this.id=sites.size();
    sites.add(this);
  }
  this.line=line;
  this.column=column;
}

public AllocationSite ( int line , int column ) { synchronized ( sites ) { this . id = sites . size ( ) ; sites . add ( this ) ; } this . line = line ; this . column = column ; }
create an allocation site for a given source code line / column .
