function preparePluginsForLocal(isBeta) {
  return (done) => {
    const pluginsDirectory = 'plugins';
    if (isBeta) {
      execSync(`npx lerna exec -- npm install blockly@beta --force `, {
        cwd: pluginsDirectory,
        stdio: 'inherit',
      });
    }
    execSync(`npm run boot`, {stdio: 'inherit'});
    // Bundles all the plugins.
    execSync(`npm run deploy:prepare:plugins`, {stdio: 'inherit'});
    done();
  };
}
Prepares plugins to be tested locally.
@param {boolean} isBeta True if we want to test gh pages with the beta
    version of Blockly.
@returns {Function} Gulp task.