text: class MinStack:
  
      def __init__(self):
          """
          initialize your data structure here.
          """
          self._items = []
  
      def push(self, val: int) -> None:
          self._items.append(val)
  
      def pop(self) -> None:
          return self._items.pop()
  
      def top(self) -> int:
          return self._items[-1]
  
      def getMin(self) -> int:
          return min(self._items)
  
  
  # Your MinStack object will be instantiated and called as such:
  # obj = MinStack()
  # obj.push(val)
  # obj.pop()
  # param_3 = obj.top()
  # param_4 = obj.getMin()