title: How to apply .OR in joi validation
body: <p>Well, i have the following Joi object, im trying to use Or method, as you see i have two objects contains phone i wanted to use Or method but i got failed  </p>
  
  <pre><code>body: Joi.object().keys({
              member: Joi.object().required().keys({
                  id: Joi.string().required(),
                  phone: Joi.string().max(30),
                  email: Joi.string().required().max(255)
              }),
              billingAddress: Joi.object().keys({
                  line1: Joi.string().required(),
                  line2: Joi.string().max(60),
                  city: Joi.string().required().max(50),
                  state: Jio.required(),
                  postalCode: Joi.string().required(),
                  phone: Joi.string().max(15)
              })
  }).or('member.phone','billingAddress.phone')
  </code></pre>
  
  <p>what im trying to do is i need a phone either to be in <strong>member.phone</strong> or in <strong>billingAddress.phone</strong> at least one of them is exist 
  the code above is not working What should i do ?</p>