[Demonstration 1]

[Buggy Method]
public String getDequeuInstruction() {
    if (dequeuInstruction == null) {
        dequeuInstruction = Json.createObjectBuilder().add("instruction", "dequeue").add("post_work_activity_sid", getWorkFlowSID()).build().toString();
    }
    return dequeuInstruction;
}

[Buggy Hunk]
.add("post_work_activity_sid", getWorkFlowSID())

[Patch]
.add("post_work_activity_sid", getPostWorkActivitySID())

[Demonstration 2]

[Buggy Method]
public static String genColumnAlias(Expr expr) {
    String a;
    if (expr instanceof ColNameExpr) {
        a = expr.getText();
    } else {
        a = String.format("%s_%d", expr.getText().substring(0, 1), column_alias_num);
    }
    column_alias_num++;
    return a;
}

[Buggy Hunk]
a = expr.getText();

[Patch]
a = ((ColNameExpr) expr).getCol();

[Demonstration 3]

[Buggy Method]
@Override
public String toString() {
    return MoreObjects.toStringHelper(Compatibility.class).add("compatible", "source").add("source", source).add("rule", rule).toString();
}

[Buggy Hunk]
return MoreObjects.toStringHelper(Compatibility.class).add("compatible", "source").add("source", source).add("rule", rule).toString();

[Patch]
return MoreObjects.toStringHelper(Compatibility.class).add("compatible", compatible).add("source", source).add("rule", rule).toString();