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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 get_strings_to_translate(self, po):
 """Return list of string to translate from po file. :param po: POFile object to translate :type po: polib.POFile :return: list of string to translate :rtype: collections.Iterable[six.text_type] """

        strings = []
        for index, entry in enumerate(po):
            if not self.need_translate(entry):
                continue
            strings.append(humanize_placeholders(entry.msgid))
            if entry.msgid_plural:
                strings.append(humanize_placeholders(entry.msgid_plural))
        return strings