### Question:
Node implements Comparable<Node> { @Override public int hashCode() { int hash = 12; hash = hash * 17 + x; hash = hash * 31 + y; return hash; } Node(int x, int y); int setParent(Node parent); void setCost(double cost); void setHeuristic(double heuristic); void setDepth(int depth); int getX(); int getY(); double getCost(); Node getParent(); double getHeuristic(); int getDepth(); @Override int compareTo(Node other); @Override boolean equals(Object object); @Override int hashCode(); @Override String toString(); String toStringCoordinates();  }### Answer:
@Test void testHashCode() { final Node hash = new Node(0, 1); assertHashEquals(hash, new Node(0, 1)); assertHashNotEquals(hash, new Object()); assertHashNotEquals(hash, new Node(0, 0)); assertHashNotEquals(hash, new Node(1, 0)); assertHashNotEquals(hash, new Node(1, 1)); }