#vulnerable code 
                              public <T> BindingBuilderImpl<T> bind(Key<T> key) {
    ensureNotCreated();
    BindingBuilderImpl<T> builder = new BindingBuilderImpl<T>(this, key, source());
    bindingBuilders.add(builder);
    return builder;
  } 
                            #location 2 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                              public <T> BindingBuilderImpl<T> bind(Key<T> key) {
    BindingBuilderImpl<T> builder = new BindingBuilderImpl<T>(this, key, source());
    bindingBuilders.add(builder);
    return builder;
  }