### Question:
ColumnDefinitionTableModel extends AbstractTableModel { @Override public int getColumnCount() { return ourColumnNames.length; }  void addRows(List<ColumnDefinitionRow> rows); void clear(); @Override Class<?> getColumnClass(int columnIndex); @Override int getColumnCount(); @Override String getColumnName(int column); ColumnDefinitionRow getRow(int rowIndex); @Override int getRowCount(); @Override Object getValueAt(int rowIndex, int columnIndex); @Override boolean isCellEditable(int rowIndex, int columnIndex); boolean isImportAllColumns(); void setFormatEditable(boolean isEditable); @Override void setValueAt(Object aValue, int rowIndex, int columnIndex);  }### Answer:
@Test public void testGetColumnCount() { ColumnDefinitionTableModel model = new ColumnDefinitionTableModel(); assertEquals(4, model.getColumnCount()); }