@Override
  public void removeCriticalMember(DistributedMember member) {
    if (logger.isDebugEnabled()) {
      logger.debug("PR: removing member {} from critical member list", member);
    }
    getRegionAdvisor().markBucketsOnMember(member, false/* sick */);
  }
Changes the CustomExpiry for idleTimeout for values in the region

@param custom the new CustomExpiry
@return the old CustomExpiry
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegion.java