@SuppressWarnings("unchecked")
    public Map<String, Object> getNested(String columnName) {
        Object value = get(columnName);
        if (value == null) {
            throw new IllegalArgumentException("No value for: " + columnName);
        }
        if (!(value instanceof Map)) {
            throw new IllegalArgumentException("Value for: " + columnName + " is not a Map, but a: " + value.getClass());
        }
        return (Map<String, Object>) value;
    }
@ SuppressWarnings ( "unchecked" ) public Map < String , Object > getNested ( String columnName ) { Object value = get ( columnName ) ; if ( value == null ) { throw new IllegalArgumentException ( "No value for: " + columnName ) ; } if ( ! ( value instanceof Map ) ) { throw new IllegalArgumentException ( "Value for: " + columnName + " is not a Map, but a: " + value . getClass ( ) ) ; } return ( Map < String , Object > ) value ; }
@param columnName
column to get current row's value of
@return value for specified column.