code: package epmc.imdp.lump;
  
  import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
  
  public final class ClassToNumberTIntIntMap implements ClassToNumber {
      public final static class Builder implements ClassToNumber.Builder {
          @Override
          public Builder setSize(int size) {
              return this;
          }
  
          @Override
          public ClassToNumber build() {
              return new ClassToNumberTIntIntMap(this);
          }
  
      }
  
      private final Int2IntOpenHashMap hash = new Int2IntOpenHashMap();
  
      private ClassToNumberTIntIntMap(Builder builder) {
          hash.defaultReturnValue(-1);
          assert builder != null;
      }
  
      @Override
      public void reset() {
          hash.clear();
      }
  
      @Override
      public int get(int classs) {
          return hash.get(classs);
      }
  
      @Override
      public void set(int classs, int number) {
          hash.put(classs, number);
      }
  }
  