@atlaskit/portal/dist/es2019/internal/utils/create-atlaskit-portal.js

A wrapper for rendering components in React portals.

import { portalClassName } from '../constants';
const isDocumentDefined = () => {
  return document !== undefined;
};
export const createAtlaskitPortal = zIndex => {
  //atlaskit-portal div
  if (isDocumentDefined()) {
    const atlaskitportal = document.createElement('div');
    atlaskitportal.className = portalClassName;
    atlaskitportal.style.zIndex = `${zIndex}`;
    return atlaskitportal;
  }
  return;
};