You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: test_applydp.rs
    path of file: ./repos/qsv/tests
    
    the code of the file until where you have to start completion: use crate::workdir::Workdir;

#[test]
fn applydp_ops_unknown_operation() {
    let wrk = Workdir::new("unknown_op");
    wrk.create(
        "data.csv",
        vec![svec!["letter", "number"], svec!["a", "1"], svec!["b", "2"]],
    );
    let mut cmd = wrk.command("applydp");
    cmd.arg("operations")
        .arg("obfuscate")
        .arg("letter")
        .arg("data.csv");

    let got: String = wrk.output_stderr(&mut cmd);
    assert_eq!(&*got, "usage error: Unknown 'obfuscate' operation\n")
}

#[test]
fn applydp_ops_upper() {
    let wrk = Workdir::new("applydp");
    wrk.create(
        "data.csv",
        vec![
            svec!["name", "
    
fn applydp_ops_regex_replace() {
    let wrk = Workdir::new("applydp");
    wrk.create(
        "data.csv",
        vec![
            svec!["description"],
            svec!["My SSN is 078-05-1120. Please do not share it."],
            svec!["twinkle, twinkle brownie star, how I wonder what you are"],
            svec!["Somebody from Nigeria called asked for my ssn - 987-65-4320."],
            svec!["Won't fall for that scam!"],
            svec!["Just enter 987-65-4329 when prompted. Also try 987-65-1234 if it doesn't work."],
        ],
    );
    let mut cmd = wrk.command("applydp");
    cmd.arg("operations")
        .arg("regex_replace")
        .arg("description")
        .arg("--comparand")
        .arg("(?:\\d{3}-\\d{2}-\\d{4})")
        .arg("--replacement")
        .arg("SSN")
        .arg("data.csv");

    let got: Vec<Vec<String>> = wrk.read_stdout(&mut cmd);
    let expected = vec![
        svec!["description"],
        svec!["My SSN is SSN. Please do not share it."],
        svec!["twinkle, twinkle brownie star, how I wonder what you are"],
        svec!["Somebody from Nigeria called asked for my ssn - SSN."],
        svec!["Won't fall for that scam!"],
        svec!["Just enter SSN when prompted. Also try SSN if it doesn't work."],
    ];
    assert_eq!(got, expected);
}