android/guava/src/com/google/common/collect/CompactHashSet.java
void moveLastEntry(int dstIndex) {
    int srcIndex = size() - 1;
    if (dstIndex < srcIndex) {
      // move last entry to deleted spot
      elements[dstIndex] = elements[srcIndex];
      elements[srcIndex] = null;

      // move the last entry to the removed spot, just like we moved the element
      long lastEntry = entries[srcIndex];
      entries[dstIndex] = lastEntry;
      entries[srcIndex] = UNSET;

      // also need to update whoever's "next" pointer was pointing to the last entry place
      // reusing "tableIndex" and "next"; these variables were no longer needed
      int tableIndex = getHash(lastEntry) & hashTableMask();
      int lastNext = table[tableIndex];
      if (lastNext == srcIndex) {
        // we need to update the root pointer
        table[tableIndex] = dstIndex;
      } else {
        // we need to update a pointer in an entry
        int previous;
        long entry;
        do {
          previous = lastNext;
          lastNext = getNext(entry = entries[lastNext]);
        } while (lastNext != srcIndex);
        // here, entries[previous] points to the old entry location; update it
        entries[previous] = swapNext(entry, dstIndex);
      }
    } else {
      elements[dstIndex] = null;
      entries[dstIndex] = UNSET;
    }
  }
void moveLastEntry(int dstIndex) {
    int srcIndex = size() - 1;
    if (dstIndex < srcIndex) {
      // move last entry to deleted spot
      elements[dstIndex] = elements[srcIndex];
      elements[srcIndex] = null;

      // move the last entry to the removed spot, just like we moved the element
      long lastEntry = entries[srcIndex];
      entries[dstIndex] = lastEntry;
      entries[srcIndex] = UNSET;

      // also need to update whoever's "next" pointer was pointing to the last entry place
      // reusing "tableIndex" and "next"; these variables were no longer needed
      int tableIndex = getHash(lastEntry) & hashTableMask();
      int lastNext = table[tableIndex];
      if (lastNext == srcIndex) {
        // we need to update the root pointer
        table[tableIndex] = dstIndex;
      } else {
        // we need to update a pointer in an entry
        int previous;
        long entry;
        do {
          previous = lastNext;
          lastNext = getNext(entry = entries[lastNext]);
        } while (lastNext != srcIndex);
        // here, entries[previous] points to the old entry location; update it
        entries[previous] = swapNext(entry, dstIndex);
      }
    } else {
      elements[dstIndex] = null;
      entries[dstIndex] = UNSET;
    }
  }
Moves the last entry in the entry array into {@code dstIndex}, and nulls out its old position.