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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 validate_length(self, value):
 """Validate the length of value, if min_length or max_length was specified"""

        list_len = len(value) if value else 0

        if self.max_length is not None and list_len > self.max_length:
            raise ValidationError(
                u'List has {} values; max length is {}'.format(list_len, self.max_length))

        if self.min_length is not None and list_len < self.min_length:
            raise ValidationError(
                u'List has {} values; min length is {}'.format(list_len, self.min_length))