HagglingCode.java

public class Placeholder {

  private final Map<String, Integer> preferences;
  private final Map<String, Integer> counts;

  public Placeholder(Map<String, Integer> preferences, Map<String, Integer> counts){ 
    this.preferences = preferences;
    this.counts = counts;
  }
  
  public Map<String, Integer> accept(Map<String, Integer> offer, int countdown) {
    // TODO - implement code here ...
    return null;
  }
}