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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 lines(self) -> str: """Return the source code lines for this error."""

        if self.definition is None:
            return ''
        source = ''
        lines = self.definition.source
        offset = self.definition.start  # type: ignore
        lines_stripped = list(reversed(list(dropwhile(is_blank,
                                                      reversed(lines)))))
        numbers_width = len(str(offset + len(lines_stripped)))
        line_format = '{{:{}}}:{{}}'.format(numbers_width)
        for n, line in enumerate(lines_stripped):
            if line:
                line = ' ' + line
            source += line_format.format(n + offset, line)
            if n > 5:
                source += '        ...\n'
                break
        return source