cleanup and addressing of pr feedback

Signed-off-by: Atanas Atanasov <a.v.atanasov98@gmail.com>

Author: ata-nas

block-node/app/src/testFixtures/java/org/hiero/block/node/app/fixtures/blocks/InMemoryBlockAccessor.java

@@ -4,7 +4,6 @@
 import com.hedera.hapi.block.stream.Block;
 import com.hedera.hapi.block.stream.BlockItem;
 import java.util.List;
-import java.util.Objects;
 import org.hiero.block.node.spi.historicalblocks.BlockAccessor;
 
 /**
@@ -39,8 +38,7 @@ public InMemoryBlockAccessor(final List<BlockItem> blockItems) {
         }
         // Create a Block from the provided block items
         block = Block.newBuilder().items(blockItems).build();
-        blockNumber =
-                Objects.requireNonNull(block.items().getFirst().blockHeader()).number();
+        blockNumber = block.items().getFirst().blockHeader().number();
     }
 
     /**

block-node/app/src/testFixtures/java/org/hiero/block/node/app/fixtures/plugintest/SimpleInMemoryHistoricalBlockFacility.java

@@ -147,8 +147,14 @@ public void clearTemporaryAvailableBlocks() {
 
     /**
      * {@inheritDoc}
-     *
      * <p>
+     * If a temporary override is set using
+     * {@link #setTemporaryAvailableBlocks(SimpleBlockRangeSet)}, then that
+     * override will be returned until cleared with
+     * {@link #clearTemporaryAvailableBlocks()}. Any updates to the available
+     * blocks in the facility will not affect the temporary override. They will
+     * be reflected however in the original available blocks set (accessible
+     * when there is no override).
      */
     @Override
     public BlockRangeSet availableBlocks() {

block-node/block-providers/files.historic/src/main/java/org/hiero/block/node/blocks/files/historic/BlocksFilesHistoricPlugin.java

@@ -197,9 +197,9 @@ public BlockRangeSet availableBlocks() {
      */
     @Override
     public void handlePersisted(PersistedNotification notification) {
-        // all operations here until we release the caller thread are queued up
+        // all operations are queued up here until we release the caller thread
         // by the block messaging facility, so we can safely perform
-        // calculations and decide if we will submit or not a task
+        // calculations and decide if we will submit a task or not
         if (notification.blockProviderPriority() > defaultPriority()) {
             attemptZipping();
         }