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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 count_lines(self, file_name):
 """ Uses the command-line utility wc to count the number of lines in a file. For MacOS, must strip leading whitespace from wc. :param str file_name: name of file whose lines are to be counted """

        x = subprocess.check_output("wc -l " + file_name + " | sed -E 's/^[[:space:]]+//' | cut -f1 -d' '", shell=True)
        return x.strip()