### Question:
GridCellTuple implements RequiresResize { @Override public void onResize() { final GridColumn<?> parentColumn = gridWidget.getModel().getColumns().get(columnIndex); parentColumn.setWidth(parentColumn.getWidth()); } GridCellTuple(final int rowIndex,
                         final int columnIndex,
                         final GridWidget gridWidget); int getRowIndex(); void setRowIndex(final int rowIndex); int getColumnIndex(); void setColumnIndex(final int columnIndex); GridWidget getGridWidget(); void proposeContainingColumnWidth(final double proposedWidth,
                                             final Function<BaseExpressionGrid, Double> requiredWidthSupplier); @Override void onResize();  }### Answer:
@Test public void testOnResizeSetsColumnWidth() { when(gridColumn.getWidth()).thenReturn(100.0); tuple.onResize(); verify(gridColumn).setWidth(100.0); }