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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 from_conll(this_class, stream):
 """Construct a Sentence. stream is an iterable over strings where each string is a line in CoNLL-X format. If there are multiple sentences in this stream, we only return the first one."""

        stream = iter(stream)
        sentence = this_class()
        for line in stream:
            line = line.strip()
            if line:
                sentence.append(Token.from_conll(line))
            elif sentence:
                return sentence
        return sentence