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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 line_number_area_width(self):
 """ Computes the lineNumber area width depending on the number of lines in the document :return: Widtg """

        digits = 1
        count = max(1, self.editor.blockCount())
        while count >= 10:
            count /= 10
            digits += 1
        space = 5 + self.editor.fontMetrics().width("9") * digits
        return space