code: @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;
      }
docs: Gets the person with the specified name.
  
  @param name the name of the person
  @return the Person instance with the specified name (or null if it doesn't exist)
  @throws IllegalArgumentException if the name is null or empty