code: public static @Nullable
      User getById(String id, boolean create) {
          return getOrCreateById(id, id, create);
      }
docs: Gets the {@link User} object by its <code>id</code>
  
  @param id     the id of the user to retrieve and optionally create if it does not exist.
  @param create If <code>true</code>, this method will never return <code>null</code> for valid input (by creating a
  new {@link User} object if none exists.) If <code>false</code>, this method will return
  <code>null</code> if {@link User} object with the given id doesn't exist.
  @return the a User whose id is <code>id</code>, or <code>null</code> if <code>create</code> is <code>false</code>
  and the user does not exist.
  @since 1.651.2 / 2.3