input: Write a function to optimize the given Python code that removes duplicate elements from an array using built-in functions. The function should return the array without duplicates.
  assert removeDuplicates([1, 2, 2, 3, 4, 4, 5])==[1, 2, 3, 4, 5]
  assert removeDuplicates([5, 5, 5, 5, 5])==[5]
  assert removeDuplicates([])==[]
  assert removeDuplicates([1, 1, 2, 3, 3, 4, 4, 4])==[1, 2, 3, 4]
output: def removeDuplicates(arr):
      return list(set(arr))