How to create primary constructor and multiple secondary constructors in Kotlin?

Follow the code: 

class ModelClass(
    var title: String,    var buttonPosTxt: String,    var buttonNegTxt: String,    var buttonNeuTxt: String,    var subTitle: String
) {

    // PopUp with Title and 1 button    constructor(
        title: String,        buttonPosTxt: String
    ) : this(title, buttonPosTxt, "", "", "")

    // PopUp with Title and 2 buttons    constructor(
        title: String,        buttonPosTxt: String,        buttonNegTxt: String
    ) : this(title, buttonPosTxt, buttonNegTxt, "", "")

    // PopUp with Title, SubTitle, 2 Buttons    constructor(
        title: String,        buttonPosTxt: String,        buttonNegTxt: String,        subTitle: String
    ) : this(title, buttonPosTxt, buttonNegTxt, "", subTitle)

}

Alternativeways: 

class ModelClass(
    var title: String,    var buttonOneTxt: String
    ){
    // Model with Title and 2 buttons    constructor( title: String,                 buttonOneTxt: String,                 buttonTwoTxt : String
                ): this(title, buttonOneTxt)

    // Model with Title, SubTitle, 2 Buttons    constructor( title: String,                 buttonOneTxt: String,                 buttonTwoTxt: String,                 subTitle: String
                 ): this(title, buttonOneTxt)

    // Model with Title, SubTitle, 3 Buttons    constructor( title: String,                 buttonOneTxt: String,                 buttonTwoTxt: String,                 buttonThreeTxt: String,                 subTitle: String
                 ): this(title, buttonOneTxt)

    // ..... you can add more constructors in this ways 
}