code: public static void addSampler(Sampler sampler) {
      synchronized (samplerLock) {
        Sampler[] samplers = additionalSamplers;
        /* create a new list of samplers from the old, adding this sampler */
        if (samplers != null) {
          Sampler[] newSamplers = new Sampler[samplers.length + 1];
          System.arraycopy(samplers, 0, newSamplers, 0, samplers.length);
          newSamplers[samplers.length] = sampler;
          additionalSamplers = newSamplers;
        } else {
          Sampler[] newSamplers = new Sampler[1];
          newSamplers[0] = sampler;
          additionalSamplers = newSamplers;
        }
      }
    }
docs: Adds a {@link Sampler} that will get run <b>every time an allocation is performed from Java
  code</b>. Use this with <b>extreme</b> judiciousness!
  
  @param sampler The sampler to add.