for (BlockLocation loc : blockLocations) {
if (!(loc instanceof HdfsBlockLocation)) {
throw new ClassCastException("DFSClient#getVolumeBlockLocations " +
"expected to be passed HdfsBlockLocations");
}
HdfsBlockLocation hdfsLoc = (HdfsBlockLocation) loc;
blocks.add(hdfsLoc.getLocatedBlock());
}
// Re-group the LocatedBlocks to be grouped by datanodes, with the values
// a list of the LocatedBlocks on the datanode.
Map<DatanodeInfo, List<LocatedBlock>> datanodeBlocks =