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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 create_superuser(self, email, password, **extra_fields):
 """Save new User with is_staff and is_superuser set to True"""

        extra_fields.setdefault('is_staff', True)
        extra_fields.setdefault('is_superuser', True)
        if extra_fields.get('is_staff') is not True:
            raise ValueError('Superuser must have is_staff=True.')
        if extra_fields.get('is_superuser') is not True:
            raise ValueError('Superuser must have is_superuser=True.')
        return self._create_user(email, password, **extra_fields)