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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 _version_from_file(lines):
 """ Given an iterable of lines from a Metadata file, return the value of the Version field, if present, or None otherwise. """

    def is_version_line(line):
        return line.lower().startswith('version:')
    version_lines = filter(is_version_line, lines)
    line = next(iter(version_lines), '')
    _, _, value = line.partition(':')
    return safe_version(value.strip()) or None