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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 _tokenize_wkt(tokens):
 """ Since the tokenizer treats "-" and numeric strings as separate values, combine them and yield them as a single token. This utility encapsulates parsing of negative numeric values from WKT can be used generically in all parsers. """

    negative = False
    for t in tokens:
        if t == '-':
            negative = True
            continue
        else:
            if negative:
                yield '-%s' % t
            else:
                yield t
            negative = False