docs: update Dirty Flag docs (#2908)

dirty-flag/src/main/java/com/iluwatar/dirtyflag/DataFetcher.java

@@ -40,7 +40,7 @@ import lombok.extern.slf4j.Slf4j;
 @Slf4j
 public class DataFetcher {
 
-  private final String filename = "world.txt";
+  private static final String FILENAME = "world.txt";
   private long lastFetched;
 
   public DataFetcher() {
@@ -62,14 +62,14 @@ public class DataFetcher {
    */
   public List<String> fetch() {
     var classLoader = getClass().getClassLoader();
-    var file = new File(classLoader.getResource(filename).getFile());
+    var file = new File(classLoader.getResource(FILENAME).getFile());
 
     if (isDirty(file.lastModified())) {
-      LOGGER.info(filename + " is dirty! Re-fetching file content...");
+      LOGGER.info(FILENAME + " is dirty! Re-fetching file content...");
       try (var br = new BufferedReader(new FileReader(file))) {
         return br.lines().collect(Collectors.collectingAndThen(Collectors.toList(), List::copyOf));
       } catch (IOException e) {
-        e.printStackTrace();
+        LOGGER.error("An error occurred: ", e);
       }
     }
 

dirty-flag/src/main/resources/world.txt

@@ -1,26 +1,3 @@
-====
-    The MIT License
-    Copyright © 2014-2021 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-====
-
 UNITED_KINGDOM
 MALAYSIA
 UNITED_STATES

dirty-flag/src/test/java/org/dirty/flag/AppTest.java

@@ -36,7 +36,6 @@ class AppTest {
 
   /**
    * Issue: Add at least one assertion to this test case.
-   *
    * Solution: Inserted assertion to check whether the execution of the main method in {@link App#main(String[])}
    * throws an exception.
    */