### Question:
GridPaneAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.GridPaneListener { public void columnCountChanged(org.apache.pivot.wtk.GridPane arg0, int arg1) { if (columnCountChanged != null) { columnCountChanged.call(arg0, arg1); } }  CallableWithArgs<Void> getColumnCountChanged(); CallableWithArgs<Void> getCellInserted(); CallableWithArgs<Void> getCellsRemoved(); CallableWithArgs<Void> getCellUpdated(); CallableWithArgs<Void> getRowsRemoved(); CallableWithArgs<Void> getRowInserted(); void setColumnCountChanged(CallableWithArgs<Void> columnCountChanged); void setCellInserted(CallableWithArgs<Void> cellInserted); void setCellsRemoved(CallableWithArgs<Void> cellsRemoved); void setCellUpdated(CallableWithArgs<Void> cellUpdated); void setRowsRemoved(CallableWithArgs<Void> rowsRemoved); void setRowInserted(CallableWithArgs<Void> rowInserted); void columnCountChanged(org.apache.pivot.wtk.GridPane arg0, int arg1); void cellInserted(org.apache.pivot.wtk.GridPane.Row arg0, int arg1); void cellsRemoved(org.apache.pivot.wtk.GridPane.Row arg0, int arg1, org.apache.pivot.collections.Sequence<Component> arg2); void cellUpdated(org.apache.pivot.wtk.GridPane.Row arg0, int arg1, org.apache.pivot.wtk.Component arg2); void rowsRemoved(org.apache.pivot.wtk.GridPane arg0, int arg1, org.apache.pivot.collections.Sequence<GridPane.Row> arg2); void rowInserted(org.apache.pivot.wtk.GridPane arg0, int arg1);  }### Answer:
@Test public void testColumnCountChanged() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getColumnCountChanged()); adapter.columnCountChanged(null, 0); assertFalse(invoked[0]); adapter.setColumnCountChanged(callable); adapter.columnCountChanged(null, 0); assertTrue(invoked[0]); }