<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def content_type(self):
 """ Get the Content-Type option of a response. :return: the Content-Type value or 0 if not specified by the response """

        value = 0
        for option in self.options:
            if option.number == defines.OptionRegistry.CONTENT_TYPE.number:
                value = int(option.value)
        return value