### Question:
StackWithQuickMinOperation { public Integer peekMin() { return minStack.peekFirst(); } StackWithQuickMinOperation(); void push(Integer value); Integer pop(); Integer peek(); Integer peekMin(); int size();  }### Answer:
@Test public void testPeekMin() { StackWithQuickMinOperation stack = new StackWithQuickMinOperation(); stack.push(10); assertThat(stack.peekMin(), is(10)); stack.push(11); assertThat(stack.peekMin(), is(10)); stack.push(12); assertThat(stack.peekMin(), is(10)); stack.push(9); assertThat(stack.peekMin(), is(9)); stack.push(8); assertThat(stack.peekMin(), is(8)); stack.push(15); assertThat(stack.peekMin(), is(8)); stack.push(1); stack.push(2); assertThat(stack.peekMin(), is(1)); }