def is_config_or_test(example, scan_width=5, coeff=0.05):
    """Check if file is a configuration file or a unit test by :
    1- looking for keywords in the first few lines of the file.
    2- counting number of occurence of the words 'config' and 'test' with respect to number of lines.
    """

    keywords = ["unit tests", "test file", "configuration file"]
    lines = example["content"].splitlines()
    count_config = 0
    count_test = 0
    # first test
    for _, line in zip(range(scan_width), lines):
        for keyword in keywords:
            if keyword in line.lower():
                return {"config_or_test": True}
    # second test
    nlines = example["content"].count("\n")
    threshold = int(coeff * nlines)
    for line in lines:
        count_config += line.lower().count("config")
        count_test += line.lower().count("test")
        if count_config > threshold or count_test > threshold:
            return {"config_or_test": True}
    return {"config_or_test": False}