feat(objectionary#274): fix all the code offences

Author: volodya-lombrozo

src/test/java/benchmarks/ProgramsBench.java

@@ -62,6 +62,7 @@ public class ProgramsBench {
      */
     private final Path home;
 
+    @SuppressWarnings("PMD.ConstructorOnlyInitializesOrCallOtherConstructors")
     public ProgramsBench() {
         try {
             this.home = Files.createTempDirectory("tmp");

src/test/java/fixtures/LargeXmir.java

@@ -43,12 +43,22 @@
  */
 public final class LargeXmir implements Scalar<XML> {
 
+    /**
+     * Name of the program.
+     */
     private final String name;
 
+    /**
+     * Constructor.
+     */
     public LargeXmir() {
         this("unknown");
     }
 
+    /**
+     * Constructor.
+     * @param nme Program name.
+     */
     public LargeXmir(final String nme) {
         this.name = nme;
     }