input: Write a function to remove all duplicates from an array of strings and return the resulting array. If the input array is empty, return an empty array.
  def removeDuplicates(arr):
      result = []
      for i in arr:
          if i not in result:
              result.append(i)
      return result
  
  assert removeDuplicates(['a', 'b', 'a', 'c', 'c', 'd'])==['a', 'b', 'c', 'd']
  assert removeDuplicates(['hello', 'world', 'hello', 'python', 'world'])==['hello', 'world', 'python']
  assert removeDuplicates(['unique'])==['unique']
  assert removeDuplicates([])==[]
output: def removeDuplicates(arr):
      result = []
      for i in arr:
          if i not in result:
              result.append(i)
      return result