How and where in ES6 will it be correct to put propTypes?

Question

JavaScript

propTypes: {
        data: React.PropTypes.object.isRequired
    },

static doesn't work. I can't make changes to the project at the dependency update level

Answer 1

class SomeComponent extends React.Component {
    ...
}

SomeComponent.propTypes = {
  data: React.PropTypes.object.isRequired
}

Answer 2

class SomeComponent extends React.Component {
    get propTypes() {
         return {
             data: React.PropTypes.object.isRequired
         };
    }
}

Answer 3

class SomeComponent extends React.Component {
  static propTypes = {
    data: React.PropTypes.object.isRequired
  }
}