Method constructor

src/core/layouts/Layout.js:6–14

(key, getObject, children)

class Layout {
  constructor(key, getObject, children) {
    this.key = key;
    this.getObject = getObject;
    this.children = children.map(key => this.getObject(key));
    this.weights = children.map(() => 1);
    this.ref = React.createRef();

    this.handleChangeWeights = this.handleChangeWeights.bind(this);
  }

  add(key, index = this.children.length) {
    const child = this.getObject(key);