code: public List<Object> getAsList(String field, String separator) {
          Object value = get(field);
          if (value == null) {
              return Collections.emptyList();
          } else {
              if (value instanceof List) {
                  return (List) value;
              } else {
                  return Arrays.<Object>asList(value.toString().split(separator));
              }
          }
      }
docs: Get the field as List. If field was not a list, returns an UnmodifiableList.
  Do not modify the ObjectMap content.
  
  @param field
  @param separator
  @return