DataTable { public void addBlankColumn(int index) { for(List<String> row : this.data) { row.add(index, ""); } } DataTable(int pageNumber);  DataTable(Collection<Integer> pageNumbers); DataTable addRow(String... dataRow); void addRow(List<String> dataRow); void addRows(List<List<String>> dataRows); List<String> headerRow(); List<String> headerRowIgnoreBlanks(); boolean hasSameHeaderAs(DataTable other); boolean hasSameHeaderBlanksIgnoredAs(DataTable other); boolean hasSameColumnCountAs(DataTable other); List<List<String>> getData(); TreeSet<Integer> getPageNumbers(); DataTable mergeWith(DataTable other); String getPagesAsString(); boolean hasData(); int getColumnsCount(); int getRowsCount(); List<String> getColumn(int c); List<String> getRow(int r); DataTable mergeColumns(int c1, int c2); void addBlankColumn(int index); @Override String toString();  }
@Test public void addBlankColumn() { DataTable dt = new DataTable(1); dt.addRow("H1", "H2", "H3"); dt.addRow("A1", "A2", "A3"); dt.addBlankColumn(1); assertThat(dt.getRow(0), is(Arrays.asList("H1", "", "H2", "H3"))); assertThat(dt.getRow(1), is(Arrays.asList("A1", "", "A2", "A3"))); }