code: func (t *Table) SetSelectedFunc(handler func(row, column int)) *Table {
  	t.selected = handler
  	return t
  }
docs: // SetSelectedFunc sets a handler which is called whenever the user presses the
  // Enter key on a selected cell/row/column. The handler receives the position of
  // the selection and its cell contents. If entire rows are selected, the column
  // index is undefined. Likewise for entire columns.