code: void allocArrays() {
      Preconditions.checkState(needsAllocArrays(), "Arrays already allocated");
  
      int expectedSize = modCount;
      int buckets = Hashing.closedTableSize(expectedSize, LOAD_FACTOR);
      this.table = newTable(buckets);
  
      this.entries = newEntries(expectedSize);
      this.keys = new Object[expectedSize];
      this.values = new Object[expectedSize];
    }
docs: Handle lazy allocation of arrays.