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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_string(self, name, help, required=True, default=None):
 		""" 		Add a new option with a type of String. 		:param str name: The name of the option, how it will be referenced. 		:param str help: The string returned as help to describe how the option is used. 		:param bool required: Whether to require that this option be set or not. 		:param str default: The default value for this option. If required is True and the user must specify it, set to anything but None. 		"""

		self._options[name] = Option(name, 'str', help, required, default=default)