### Question:
TableSlice extends Relation { @Override public int rowCount() { if (hasSelection()) { return selection.size(); } return table.rowCount(); } TableSlice(Table table, Selection rowSelection);  TableSlice(Table table); @Override Column<?> column(int columnIndex); @Override Column<?> column(String columnName); @Override int columnCount(); @Override int rowCount(); @Override List<Column<?>> columns(); @Override int columnIndex(Column<?> column); @Override Object get(int r, int c); @Override String name(); Table getTable(); @Override void clear(); void removeSort(); void removeSelection(); @Override List<String> columnNames(); @Override TableSlice addColumns(Column<?>... column); @Override TableSlice removeColumns(Column<?>... columns); @Override Table first(int nRows); @Override TableSlice setName(String name); Table asTable(); double reduce(String numberColumnName, NumericAggregateFunction function); @Override Iterator<Row> iterator(); int mappedRowNumber(int rowNumber); void sortOn(Sort key);  }### Answer:
@Test public void rowCount() { TableSlice slice = new TableSlice(source, Selection.withRange(0, source.rowCount())); assertEquals(source.rowCount(), slice.rowCount()); TableSlice slice1 = new TableSlice(source, Selection.withRange(0, 100)); assertEquals(100, slice1.rowCount()); }
@Test public void print() { TableSlice slice = new TableSlice(source, Selection.withRange(0, source.rowCount())); assertEquals(source.print(), slice.print()); }