input: Write a python function to append, retrieve, and remove data from a custom data structure.
  assert __name__ == '__main__':
      ds = CustomDataStructure()
      ds.appendData(10)
      ds.appendData(20)
      assert ds.getData() == [10, 20]
      ds.removeData(0)
      assert ds.getData() == [20]
      ds.appendData(30)
      assert ds.getData() == [20, 30]
      ds.removeData(1)
      assert ds.getData() == [20]
output: class CustomDataStructure:
      def __init__(self):
          self.data = []
  
      def appendData(self, value):
          self.data.append(value)
  
      def getData(self):
          return self.data
  
      def removeData(self, index):
          if 0 <= index < len(self.data):
              self.data.pop(index)