code: public Boolean getBoolean (int index) {
          String string = getString (index);
          return (string != null) ? Boolean.parseBoolean (string) : null;
      }
docs: Retrieve an indexed element and return it as a Boolean.
  
  @param index An integer value specifying the offset from the beginning of the array.
  @return The element as a Boolean, or null if the element is not found.