docs: @Nullable
      public Person getPersonWithName(@Nonnull String name) {
          if (name == null || name.trim().length() == 0) {
              throw new IllegalArgumentException("A person name must be specified.");
          }
  
          for (Person person : getPeople()) {
              if (person.getName().equals(name)) {
                  return person;
              }
          }
  
          return null;
      }