input: def modify_string_case(string: str) -> StringCaseModifier:
      """Create a class instance that modifies the case of the given string.
      The class has methods to convert the string to upper case, lower case, and title case.
      >>> modify_string_case('Hello World').to_upper()
      'HELLO WORLD'
      >>> modify_string_case('Hello World').to_lower()
      'hello world'
      >>> modify_string_case('Hello World').to_title()
      'Hello World'
      """
      return StringCaseModifier(string)
output:     
  class StringCaseModifier:
      def __init__(self, string: str):
          self.string = string
  
      def to_upper(self) -> str:
          return self.string.upper()
  
      def to_lower(self) -> str:
          return self.string.lower()
  
      def to_title(self) -> str:
          return self.string.title()
  