input: Write a class to modify the case of a given string. The class should include methods to convert the string to uppercase, lowercase, and title case.
  assert StringCaseModifier('Hello World').to_upper() == 'HELLO WORLD'
  assert StringCaseModifier('Hello World').to_lower() == 'hello world'
  assert StringCaseModifier('Hello World').to_title() == 'Hello World'
  assert StringCaseModifier('hello WORLD').to_title() == 'Hello World'
output: class StringCaseModifier:
      def __init__(self, text):
          self.text = text
  
      def to_upper(self):
          return self.text.upper()
  
      def to_lower(self):
          return self.text.lower()
  
      def to_title(self):
          return self.text.title()