builder.put("key", "value");
    assertThat(builder.build().entries()).containsExactly(Maps.immutableEntry("key", "value"));
  }

  public void testBuilderWithExpectedKeysPositive() {
    ImmutableListMultimap.Builder<String, String> builder =
        ImmutableListMultimap.builderWithExpectedKeys(1);
    builder.put("key", "value");

        joiner.setEmptyValue("");
        for (Path p : paths) {
            joiner.add(p.toString());
        }
        String value = joiner.toString();
        if (value.isEmpty()) {
            return new String[0];
        }
        return new String[] {option, value};
    }

    /**
     * {@return a string representation of this path type for debugging purposes}.
     */
    @Override

            }

            int indexOfEntryWithValue(V value) {
              for (int i = 0; i < orderedEntries.size(); i++) {
                if (equal(orderedEntries.get(i).getValue(), value)) {
                  return i;
                }
              }
              throw new IllegalArgumentException(
                  "Map.values generator can order only sample values");
            }
          });

          public String apply(String value) {
            return Ascii.toLowerCase(value);
          }
        };

    static final EntryTransformer<String, String, String> ENTRY_TRANSFORMER =
        new EntryTransformer<String, String, String>() {
          @Override
          public String transformEntry(String key, String value) {
            return Ascii.toLowerCase(value);
          }
        };
  }

         * an array and when a value is potentionally overriden it is added to the array. The single
         * arg option value is retrieved and instead of returning values[values.length-1] it returns
         * values[0] which means that the original value instead of the overridden one is returned
         * (first wins). With properties values are truely overriden since at the end a map is used

      Map<C, V> thisRow = requireNonNull(rows.get(rowKey));
      cellColumnInRowIndices[i] = thisRow.size();
      V oldValue = thisRow.put(columnKey, value);
      checkNoDuplicate(rowKey, columnKey, oldValue, value);
      requireNonNull(columns.get(columnKey)).put(rowKey, value);
    }
    this.cellRowIndices = cellRowIndices;
    this.cellColumnInRowIndices = cellColumnInRowIndices;
    ImmutableMap.Builder<R, ImmutableMap<C, V>> rowBuilder =

        Doc(
            """
            Default value if the parameter field is not set.
            """
        ),
    ] = Undefined,
    *,
    default_factory: Annotated[
        Union[Callable[[], Any], None],
        Doc(
            """
            A callable to generate the default value.

            This doesn't affect `Path` parameters as the value is always required.

          negativeToMaxValue(evictionCount.sum()));
    }

    /** Returns {@code value}, if non-negative. Otherwise, returns {@link Long#MAX_VALUE}. */
    private static long negativeToMaxValue(long value) {
      return (value >= 0) ? value : Long.MAX_VALUE;
    }

    /** Increments all counters by the values in {@code other}. */
    public void incrementBy(StatsCounter other) {

    @Override
    public boolean contains(@Nullable Object object) {
      if (object instanceof Cell) {
        Cell<?, ?, ?> cell = (Cell<?, ?, ?>) object;
        Object value = RegularImmutableTable.this.get(cell.getRowKey(), cell.getColumnKey());
        return value != null && value.equals(cell.getValue());
      }
      return false;
    }

    @Override
    boolean isPartialView() {
      return false;
    }

</div>

This means that it will **always have a value**, it's just that sometimes the value could be `None` (or `null` in JSON).

That means that, clients using your API don't have to check if the value exists or not, they can **assume the field will always be there**, but just that in some cases it will have the default value of `None`.