private BitSetNode growNode(BitSetNode node, long procId) {
    map.remove(node.getStart());
    node.grow(procId);
    map.put(node.getStart(), node);
    return node;
  }
Grows {@code node} to contain {@code procId} and updates the map.
@return {@link BitSetNode} instance which contains {@code procId}.
hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/store/wal/ProcedureStoreTracker.java