V value = getValue(index);
            if (value != null) {
              return immutableEntry(getKey(index), value);
            }
          }
          return endOfData();
        }
      };
    }

    // redeclare to help optimizers with b/310253115
    @SuppressWarnings("RedundantOverride")
    @J2ktIncompatible // serialization
    @Override

      this.nextPermutation = new ArrayList<>(list);
      this.comparator = comparator;
    }

    @Override
    protected @Nullable List<E> computeNext() {
      if (nextPermutation == null) {
        return endOfData();
      }
      ImmutableList<E> next = ImmutableList.copyOf(nextPermutation);
      calculateNextPermutation();
      return next;
    }

    void calculateNextPermutation() {
      int j = findNextJ();

          while (!elemItr.hasNext()) {
            if (rangeItr.hasNext()) {
              elemItr = ContiguousSet.create(rangeItr.next(), domain).iterator();
            } else {
              return endOfData();
            }
          }
          return elemItr.next();
        }
      };
    }

    @Override
    @GwtIncompatible("NavigableSet")

              Optional<? extends T> optional = iterator.next();
              if (optional.isPresent()) {
                return optional.get();
              }
            }
            return endOfData();
          }
        };
  }

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;

              countMap.entrySet().iterator();

          @Override
          protected @Nullable Entry<E> computeNext() {
            while (true) {
              if (!mapEntries.hasNext()) {
                return endOfData();
              }
              Map.Entry<E, AtomicInteger> mapEntry = mapEntries.next();
              int count = mapEntry.getValue().get();
              if (count != 0) {

            String next = lines.next();
            // skip last line if it's empty
            if (lines.hasNext() || !next.isEmpty()) {
              return next;
            }
          }
          return endOfData();
        }
      };
    }

    @Override
    public Stream<String> lines() {
      return stream(linesIterator());
    }

    @Override
    public @Nullable String readFirstLine() {

            String next = lines.next();
            // skip last line if it's empty
            if (lines.hasNext() || !next.isEmpty()) {
              return next;
            }
          }
          return endOfData();
        }
      };
    }

    @Override
    // If users use this when they shouldn't, we hope that NewApi will catch subsequent Stream calls
    @IgnoreJRERequirement

        while (unfiltered.hasNext()) {
          T element = unfiltered.next();
          if (retainIfTrue.apply(element)) {
            return element;
          }
        }
        return endOfData();
      }
    };
  }

  /**
   * Returns a view of {@code unfiltered} containing all elements that are of the type {@code
   * desiredType}.
   */