Extract And Move Method	package changedBetweenSnapshots(earlierSnapshot Snapshot, laterSnapshot Snapshot) : boolean extracted from package computeDiffBetweenSnapshots(fromSnapshot Snapshot, toSnapshot Snapshot, diff ChildrenDiff) : boolean in class org.apache.hadoop.hdfs.server.namenode.snapshot.INodeDirectoryWithSnapshot & moved to class org.apache.hadoop.hdfs.server.namenode.snapshot.AbstractINodeDiffList