code: public Boolean getBoolean(int index) {
          Object bool = list.get(index);
          if (bool == null) return null;
          if (bool instanceof Boolean) return (Boolean) bool;
          throw new JsonException("not a boolean");
      }
docs: Returns the {@link java.lang.Boolean} at index or null if not found.
  
  @param index
  @return the value at index or null if not found
  @throws java.lang.IndexOutOfBoundsException if the index is out of the array bounds