private void ensureCapacity(int size) {
    int countRegs = interference.size();

    interference.ensureCapacity(size);

    for (int i = countRegs; i < size; i++) {
      interference.add(SetFactory.makeInterferenceSet(size));
    }
  }
Ensures that the interference graph is appropriately sized.

@param size requested minumum size
android/android_framework/dex-maker/src/main/java/com/android/dx/ssa/back/InterferenceGraph.java