public InternalDistributedMember basicGetPrimaryMember() {
    return primaryMember.get();
  }
Check the primary member shortcut. Does not query the advisor. Should only be used when the
advisor should not be consulted directly.

@return the member or null if no primary exists
geode-core/src/main/java/org/apache/geode/internal/cache/BucketAdvisor.java