public boolean isMaximumWait(final long maximumWait) {
      return (EnvironmentEdgeManager.currentTime() - this.createTime) > maximumWait;
    }
Returns True if we have been delayed > <code>maximumWait</code> milliseconds.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MemStoreFlusher.java