private final ImmutableMap<R, ImmutableMap<C, V>> rowMap;
  private final ImmutableMap<C, ImmutableMap<R, V>> columnMap;

  @SuppressWarnings("Immutable") // We don't modify this after construction.
  private final int[] rowCounts;

  @SuppressWarnings("Immutable") // We don't modify this after construction.
  private final int[] columnCounts;

  @SuppressWarnings("Immutable") // We don't modify this after construction.

        assertEquals("Email", columns[1]);
        assertEquals("Age", columns[2]);
        assertEquals("Department", columns[3]);

        // Verify row count
        final String rowCount = extractData.getValues("row_count")[0];
        assertEquals("4", rowCount);
    }

    public void test_getText_null() {
        try {
            csvExtractor.getText(null, null);
            fail();