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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 _valid_search(self, s):
 """ Check this given `s`, it must be a string or a list of strings. Otherwise, a TypeError will be raised. """

        if isinstance(s, six.string_types):
            return lambda l: s in l
        elif (isinstance(s, list) and len(s) > 0 and
              all(isinstance(w, six.string_types) for w in s)):
            return lambda l: all(w in l for w in s)
        elif s is not None:
            raise TypeError('Search items must be given as a string or a list of strings')