### Question:
GridBase implements Grid, EventTarget { @Override public int getRowCount() { return rowCount; } GridBase(int rowCount, int columnCount); @Override ObservableList<ObservableList<SpreadsheetCell>> getRows(); @Override void setCellValue(int modelRow, int column, Object value); @Override int getRowCount(); @Override int getColumnCount(); @Override double getRowHeight(int row); void setRowHeightCallback(Callback<Integer, Double> rowHeight); @Override ObservableList<String> getRowHeaders(); @Override ObservableList<String> getColumnHeaders(); BooleanProperty lockedProperty(); boolean isLocked(); void setLocked(Boolean lock); @Override void spanRow(int count, int rowIndex, int colIndex); @Override void spanColumn(int count, int rowIndex, int colIndex); @Override void setRows(Collection<ObservableList<SpreadsheetCell>> rows); void setResizableRows(BitSet resizableRow); @Override boolean isRowResizable(int row); @Override boolean isDisplaySelection(); @Override void setDisplaySelection(boolean value); @Override BooleanProperty displaySelectionProperty(); @Override void setCellDisplaySelection(int row, int column, boolean displaySelection); @Override boolean isCellDisplaySelection(int row, int column); @Override void addEventHandler(EventType<E> eventType, EventHandler<E> eventHandler); @Override void removeEventHandler(EventType<E> eventType, EventHandler<E> eventHandler); @Override EventDispatchChain buildEventDispatchChain(EventDispatchChain tail);  }### Answer:
@Test public void testGetRowCount() { ObservableList<SpreadsheetCell> list = FXCollections.observableArrayList(); grid.getRows().add(list); assertEquals(16, grid.getRowCount()); }