react native failed child context type code example

Example 1: Warning: Failed child context type: Invalid child context `virtualizedCell.cellKey` of type

keyExtractor={(item) => item.id.toString()}

Example 2: Warning: Failed child context type: Invalid child context `virtualizedCell.cellKey` of type `number` supplied to `CellRenderer`, expected `string`.

keyExtractor={item => item.index_id.toString()}