boolean containsNode(Node check) {
    if (nodes != null) {
      return nodes.contains(check);
    } else {
      return false;
    }
  }
Safely checks to see if the provided Node participates in the PartitionedRegion return true if
the Node participates in the PartitionedRegion
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionRegionConfig.java