### Question:
TableViewColumnAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.TableViewColumnListener { public void columnWidthChanged(org.apache.pivot.wtk.TableView.Column arg0, int arg1, boolean arg2) { if (columnWidthChanged != null) { columnWidthChanged.call(arg0, arg1, arg2); } }  CallableWithArgs<Void> getColumnInserted(); CallableWithArgs<Void> getColumnsRemoved(); CallableWithArgs<Void> getColumnWidthChanged(); CallableWithArgs<Void> getColumnNameChanged(); CallableWithArgs<Void> getColumnHeaderDataChanged(); CallableWithArgs<Void> getColumnHeaderDataRendererChanged(); CallableWithArgs<Void> getColumnWidthLimitsChanged(); CallableWithArgs<Void> getColumnFilterChanged(); CallableWithArgs<Void> getColumnCellRendererChanged(); void setColumnInserted(CallableWithArgs<Void> columnInserted); void setColumnsRemoved(CallableWithArgs<Void> columnsRemoved); void setColumnWidthChanged(CallableWithArgs<Void> columnWidthChanged); void setColumnNameChanged(CallableWithArgs<Void> columnNameChanged); void setColumnHeaderDataChanged(CallableWithArgs<Void> columnHeaderDataChanged); void setColumnHeaderDataRendererChanged(CallableWithArgs<Void> columnHeaderDataRendererChanged); void setColumnWidthLimitsChanged(CallableWithArgs<Void> columnWidthLimitsChanged); void setColumnFilterChanged(CallableWithArgs<Void> columnFilterChanged); void setColumnCellRendererChanged(CallableWithArgs<Void> columnCellRendererChanged); void columnInserted(org.apache.pivot.wtk.TableView arg0, int arg1); void columnsRemoved(org.apache.pivot.wtk.TableView arg0, int arg1, org.apache.pivot.collections.Sequence<TableView.Column> arg2); void columnWidthChanged(org.apache.pivot.wtk.TableView.Column arg0, int arg1, boolean arg2); void columnNameChanged(org.apache.pivot.wtk.TableView.Column arg0, java.lang.String arg1); void columnHeaderDataChanged(org.apache.pivot.wtk.TableView.Column arg0, java.lang.Object arg1); void columnHeaderDataRendererChanged(org.apache.pivot.wtk.TableView.Column arg0, org.apache.pivot.wtk.TableView.HeaderDataRenderer arg1); void columnWidthLimitsChanged(org.apache.pivot.wtk.TableView.Column arg0, int arg1, int arg2); void columnFilterChanged(org.apache.pivot.wtk.TableView.Column arg0, java.lang.Object arg1); void columnCellRendererChanged(org.apache.pivot.wtk.TableView.Column arg0, org.apache.pivot.wtk.TableView.CellRenderer arg1);  }### Answer:
@Test public void testColumnWidthChanged() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getColumnWidthChanged()); adapter.columnWidthChanged(null, 0, false); assertFalse(invoked[0]); adapter.setColumnWidthChanged(callable); adapter.columnWidthChanged(null, 0, false); assertTrue(invoked[0]); }