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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 do_command_line(infile: typing.IO[str]) -> int: """ Currently a small stub to create an instance of Checker for the passed ``infile`` and run its test functions through linting. Args: infile Returns: int: Number of flake8 errors raised. """

    lines = infile.readlines()
    tree = ast.parse(''.join(lines))
    checker = Checker(tree, lines, infile.name)
    checker.load()
    errors = []  # type: typing.List[AAAError]
    for func in checker.all_funcs(skip_noqa=True):
        try:
            errors = list(func.check_all())
        except ValidationError as error:
            errors = [error.to_aaa()]
        print(func.__str__(errors), end='')
    return len(errors)