code: public Object read(Object value) {
          if(value instanceof List)
              return listLookup((List)value, _index);
          else if(value.getClass().isArray())
              return arrayLookup(value, _index);
          else {
              String message = "The index \"" +
              _index +
              "\" can not be used to index a property on an object that is not an Array or a List";
              LOGGER.error(message);
              throw new RuntimeException(message);
          }
      }
docs: Evaluate an array index token.  This token takes the form "[1234]" where
  "1234" is the index into the array.  The token is identified as this because
  an integer number appears between the square brackets.
  
  @param value the object from which to read a value at the index represented by this token
  @return the value of the item at this array index