input: 
  class StringCaseModifier:
      def __init__(self, string):
          self.string = string
  
      def to_upper(self):
          return self.string.upper()
  
      def to_lower(self):
          return self.string.lower()
      
      def to_title(self):
          return self.string.title()
  
  if __name__ == '__main__':
      test_string = 'Hello World'
      string_modifier = StringCaseModifier(test_string)
      print(string_modifier.to_upper())
      print(string_modifier.to_lower())
      print(string_modifier.to_title())
  
  
  The above code defines a class named `StringCaseModifier` which can be used to modify the case of a given string. The class provides three methods: `to_upper`, `to_lower`, and `to_title`, which convert the input string to uppercase, lowercase, and title case respectively. Write an instance method `to_alternating_case` that converts the string to alternating case (e.g., "HeLlO wOrLd").
  
  
  class StringCaseModifier:
      def __init__(self, string):
          self.string = string
  
      def to_upper(self):
          return self.string.upper()
  
      def to_lower(self):
          return self.string.lower()
      
      def to_title(self):
          return self.string.title()
  
      def to_alternating_case(self):
          """
          Converts the string to alternating case.
          >>> string_modifier = StringCaseModifier('Hello World')
          >>> string_modifier.to_alternating_case()
          'HeLlO wOrLd'
          """
          result = ''
          for i, char in enumerate(self.string):
              if i % 2 == 0:
                  result += char.upper()
              else:
                  result += char.lower()
          return result
  
  if __name__ == '__main__':
      test_string = 'Hello World'
      string_modifier = StringCaseModifier(test_string)
      print(string_modifier.to_upper())
      print(string_modifier.to_lower())
      print(string_modifier.to_title())
      print(string_modifier.to_alternating_case())
  
output:     
      def to_alternating_case(self):
          """
          Converts the string to alternating case.
          >>> string_modifier = StringCaseModifier('Hello World')
          >>> string_modifier.to_alternating_case()
          'HeLlO wOrLd'
          """
          result = ''
          for i, char in enumerate(self.string):
              if i % 2 == 0:
                  result += char.upper()
              else:
                  result += char.lower()
          return result
  
  if __name__ == '__main__':
      test_string = 'Hello World'
      string_modifier = StringCaseModifier(test_string)
      print(string_modifier.to_upper())
      print(string_modifier.to_lower())
      print(string_modifier.to_title())
      print(string_modifier.to_alternating_case())
  