code: public final PJsonArray getJSONArray(final String key) {
          final JSONArray val = this.obj.optJSONArray(key);
          if (val == null) {
              throw new ObjectMissingException(this, key);
          }
          return new PJsonArray(this, val, key);
      }
docs: Get a property as a json array or throw exception.
  
  @param key the property name