text: /**
   * It returns the property names of the given object.
   * 
   * @param {object} o the object
   * @returns {string[]} the list of the properties of the object
   *                     or empty array if it is not an object
   */
  
  const properties = o => (typeof o === 'object') ? Object.keys(o) : [];
  
  
  module.exports = properties;
  