Map<R, Map<C, V>> rows = new LinkedHashMap<>();
    for (R row : rowSpace) {
      rows.put(row, new LinkedHashMap<C, V>());
    }
    Map<C, Map<R, V>> columns = new LinkedHashMap<>();
    for (C col : columnSpace) {
      columns.put(col, new LinkedHashMap<R, V>());
    }
    int[] cellRowIndices = new int[cellList.size()];
    int[] cellColumnInRowIndices = new int[cellList.size()];

    Map<R, Map<C, V>> rows = new LinkedHashMap<>();
    for (R row : rowSpace) {
      rows.put(row, new LinkedHashMap<C, V>());
    }
    Map<C, Map<R, V>> columns = new LinkedHashMap<>();
    for (C col : columnSpace) {
      columns.put(col, new LinkedHashMap<R, V>());
    }
    int[] cellRowIndices = new int[cellList.size()];
    int[] cellColumnInRowIndices = new int[cellList.size()];

      /*
       * This sorting logic leads to a cellSet() ordering that may not be expected and that isn't
       * documented in the Javadoc. If a row Comparator is provided, cellSet() iterates across the
       * columns in the first row, the columns in the second row, etc. If a column Comparator is
       * provided but a row Comparator isn't, cellSet() iterates across the rows in the first
       * column, the rows in the second column, etc.
       */

 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in
 * a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still runs

 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in
 * a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still runs

/**
 * Implementation of {@code Table} whose iteration ordering across row keys is sorted by their
 * natural ordering or by a supplied comparator. Note that iterations across the columns keys for a
 * single row key may or may not be ordered, depending on the implementation. When rows and columns
 * are both sorted, it's easier to use the {@link TreeBasedTable} subclass.
 *
 * <p>The {@link #rowKeySet} method returns a {@link SortedSet} and the {@link #rowMap} method

/**
 * Implementation of {@code Table} whose iteration ordering across row keys is sorted by their
 * natural ordering or by a supplied comparator. Note that iterations across the columns keys for a
 * single row key may or may not be ordered, depending on the implementation. When rows and columns
 * are both sorted, it's easier to use the {@link TreeBasedTable} subclass.
 *
 * <p>The {@link #rowKeySet} method returns a {@link SortedSet} and the {@link #rowMap} method

        // Verify column metadata
        final String[] columns = extractData.getValues("columns");
        assertNotNull(columns);
        assertEquals(4, columns.length);
        assertEquals("Name", columns[0]);
        assertEquals("Email", columns[1]);
        assertEquals("Age", columns[2]);
        assertEquals("Department", columns[3]);

        // Verify row count

    List<V> values = asList(v0(), null, v3());
    multimap().replaceValues(k0(), values);
    assertGet(k0(), values);
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
  public void testReplaceValuesWithNullKey() {
    List<V> values = asList(v0(), v2(), v3());
    multimap().replaceValues(null, values);
    assertGet(null, values);
  }

      List<V> values = multimap().get(k);
      List<V> expectedValues = copyToList(values);

      assertTrue(multimap().put(k, v));
      expectedValues.add(v);
      assertGet(k, expectedValues);
      assertEquals(v, values.get(values.size() - 1));
    }
  }