[Demonstration 1]

[Buggy Method]
static private String convertNumberLess10(int number, boolean is_thousands) {
    if (number < 1 || number > 9) {
        throw new IllegalArgumentException("Number is " + number + ".");
    }
    if (is_thousands && number < 3) {
        return number == 1 ? "одна" : "две";
    }
    String[] numbersLess10 = new String[] { "один", "два", "три", "четыре", "пять", "шесть", "семь", "восемь", "девять" };
    return numbersLess10[number - 1];
}

[Buggy Hunk]
throw new IllegalArgumentException("Number is " + number + ".");

[Patch]
throw new IllegalArgumentException();

[Demonstration 2]

[Buggy Method]
public boolean insertRecord(String schema, String tableName, java.util.List<CoalesceParameter> parameters) throws CoalesceException {
    boolean success = false;
    StringBuilder sql = new StringBuilder("insert into ").append(schema).append(".").append(NORMALIZER.normalize(tableName)).append(" (");
    boolean first = true;
    for (CoalesceParameter parameter : parameters) {
        if (!first) {
            sql.append(",");
        } else {
            first = false;
        }
        sql.append(parameter.getName());
    }
    sql.append(") values (");
    first = true;
    for (CoalesceParameter parameter : parameters) {
        if (!first) {
            sql.append(",");
        } else {
            first = false;
        }
        if (parameter.getType() == ECoalesceFieldDataTypes.STRING_TYPE.ordinal() || parameter.getType() == ECoalesceFieldDataTypes.GUID_TYPE.ordinal()) {
            sql.append(quote(parameter.getValue()));
        } else {
            sql.append(parameter.getValue());
        }
    }
    sql.append(")");
    try {
        LOGGER.trace("Insert Record SQL: " + sql);
        Connection conn = this.getConnection();
        Statement stmt = conn.createStatement();
        stmt.executeUpdate(sql.toString());
        success = true;
    } catch (SQLException e) {
        throw new CoalesceException("Insert Record Failed", e);
    }
    return success;
}

[Buggy Hunk]
sql.append(parameter.getName());

[Patch]
sql.append(NORMALIZER.normalize(parameter.getName()));

[Demonstration 3]

[Buggy Method]
private String realiseProbabilisticModel(Object... parameters) {
    StringBuilder model = new StringBuilder();
    //process the given parameters
    //...
    //e.g. model.append(parameters[0].toString());
    return model.toString();
}

[Buggy Hunk]
StringBuilder model = new StringBuilder();

[Patch]
StringBuilder model = new StringBuilder(modelAsString + "\n\n//Variables\n");