SimpleCell implements Cell { void increaseNeighborCount() { neighborCount++; } SimpleCell(int x, int y, int state); @Override void setOverseer(Overseer overseer); @Override void reset(int state); @Override long getId(); @Override int getX(); @Override int getY(); @Override int getState(); @Override void setState(int newState); @Override boolean isAlive(); @Override boolean isDead(); @Override void onNeighborStateChange(int newState); int getNeighborCount(); @Override boolean equals(Object o); @Override int hashCode();  }
@Test public void testIncreaseNeighborCount() { assertThat(cell.neighborCount).isEqualTo(0); cell.increaseNeighborCount(); assertThat(cell.neighborCount).isEqualTo(1); }