changes as per review comments

core-java-io/src/test/java/com/baeldung/filechannel/FileChannelUnitTest.java

@@ -12,7 +12,6 @@ import java.nio.ByteBuffer;
 import java.nio.MappedByteBuffer;
 import java.nio.channels.FileChannel;
 import java.nio.channels.FileLock;
-import java.nio.channels.OverlappingFileLockException;
 import java.nio.charset.StandardCharsets;
 
 import org.junit.Test;
@@ -37,7 +36,9 @@ public class FileChannelUnitTest {
                 buff.clear();
             }
 
-			assertEquals("Hello world", new String(out.toByteArray(), StandardCharsets.UTF_8));
+            String fileContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
+
+            assertEquals("Hello world", fileContent);
         }
     }
 
@@ -58,9 +59,9 @@ public class FileChannelUnitTest {
                 out.write(buff.array(), 0, buff.position());
                 buff.clear();
             }
+            String fileContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
 
-			assertEquals("Hello world", new String(out.toByteArray(), StandardCharsets.UTF_8));
-
+            assertEquals("Hello world", fileContent);
         }
     }
 
@@ -77,9 +78,7 @@ public class FileChannelUnitTest {
                 byte[] data = new byte[buff.remaining()];
                 buff.get(data);
                 assertEquals("world", new String(data, StandardCharsets.UTF_8));
-
             }
-
         }
     }
 
@@ -90,11 +89,9 @@ public class FileChannelUnitTest {
             FileChannel channel = writer.getChannel();) {
             ByteBuffer buff = ByteBuffer.wrap("Hello world".getBytes(StandardCharsets.UTF_8));
 
-			if (buff.hasRemaining()) {
             channel.write(buff);
-			}
 
-			// verify
+            // now we verify whether the file was written correctly
             RandomAccessFile reader = new RandomAccessFile(file, "r");
             assertEquals("Hello world", reader.readLine());
             reader.close();
@@ -108,11 +105,7 @@ public class FileChannelUnitTest {
             FileLock fileLock = channel.tryLock(6, 5, Boolean.FALSE);) {
 
             assertNotNull(fileLock);
-
-		} catch (OverlappingFileLockException | IOException ex) {
-
         }
-
     }
 
     @Test
@@ -133,11 +126,11 @@ public class FileChannelUnitTest {
                 buff.clear();
             }
 
+            // the original file is 11 bytes long, so that's where the position pointer should be
             assertEquals(11, channel.position());
 
             channel.position(4);
             assertEquals(4, channel.position());
-
         }
     }
 
@@ -147,10 +140,9 @@ public class FileChannelUnitTest {
         try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); 
             FileChannel channel = reader.getChannel();) {
 
-			long imageFileSize = channel.size();
-			assertEquals(11, imageFileSize);
+            // the original file is 11 bytes long, so that's where the position pointer should be
+            assertEquals(11, channel.size());
         }
-
     }
 
     @Test