input: Write a python function to create a class that counts the elements in an array.
  assert ArrayCounter([1, 2, 3, 4]).count() == 4
  assert ArrayCounter([10, 20, 30, 40, 50]).count() == 5
  assert ArrayCounter([]).count() == 0
output: class ArrayCounter:
      def __init__(self, array):
          self.array = array
  
      def count(self):
          return len(self.array)