if (count == 0 && !isLinkedHash) {
        contents = new ObjectCountLinkedHashMap<E>(contents);
        isLinkedHash = true;
        // to preserve insertion order through deletions, we have to switch to an actual linked
        // implementation at least for now, but this should be a super rare case
      } else if (buildInvoked) {
        contents = new ObjectCountHashMap<E>(contents);
        isLinkedHash = false;
      }

            AVX512_BF16, AMX, etc.
            ([Intel Cascade Lake](https://www.intel.com/content/www/us/en/products/platforms/details/cascade-lake.html)
            and newer CPUs.)
            *   [Example performance speedups.](https://medium.com/intel-analytics-software/leverage-intel-deep-learning-optimizations-in-tensorflow-129faa80ee07)

       * in that case, getProperty *will* return null.
       *
       * TODO(b/192002623): Handle that case: Either:
       *
       * - Skip non-string keys and values entirely, as proposed in the linked bug.
       *
       * - Throw ClassCastException instead of NullPointerException, as documented in the current
       *   Javadoc. (Note that we can't necessarily "just" change our call to `getProperty` to `get`