Dad.java

public class Mom implements Replenishable{
  
  private int bankAccount;
  
  public int getCurrentAmount(bankAccount){
    // finds out the current anoint in the bank account
  }
  public int getFullAmount(bankAccount){
    // finds out how much there should be
  }
  public boolean isEmpty(){
    // returns true if the current amount is 0
    // returns false if not
  }
  public int replenish(){
    // if the current amount eqauls the full amount then it will do nothing
    // if the current amiunt does not equal the full amount then it will add half of the full amount to the current amount;
  }
}

Mom.java

public class Mom implements Replenishable{
  
  private int bankAccount;
  
  public int getCurrentAmount(bankAccount){
    // finds out the current anoint in the bank account
  }
  public int getFullAmount(bankAccount){
    // finds out how much there should be
  }
  public boolean isEmpty(){
    // returns true if the current amount is 0
    // returns false if not
  }
  public int replenish(){
    // if the current amount eqauls the full amount then it will do nothing
    // if the current amiunt does not equal the full amount then it will make them equal
  }
}

Replenishable.java

interface replenishable{
  int getAmount(int x); // returns how much of the item there is
  int getFullAmount(int x); // returns how much of the item there should be
  boolean isEmpty(); // returns whether or not thre is any more of the item
  int replenish(); // adds to the amount
  
}