/// <summary>Add recovering block to the command.</summary>
public virtual void Add(BlockRecoveryCommand.RecoveringBlock block)
{
recoveringBlocks.AddItem(block);
}
/// <summary>Initialize a replica recovery.</summary>
/// <returns>
/// actual state of the replica on this data-node or
/// null if data-node does not have the replica.
/// </returns>
/// <exception cref="System.IO.IOException"/>
public abstract ReplicaRecoveryInfo InitReplicaRecovery(BlockRecoveryCommand.RecoveringBlock
rBlock);