style: do not suppress this-escape

pom.xml

@@ -82,7 +82,6 @@
                         <arg>-Xlint:-try</arg>
                         <arg>-Xlint:-unchecked</arg>
                         <arg>-Xlint:-lossy-conversions</arg>
-                        <arg>-Xlint:-this-escape</arg>
                         <arg>-Werror</arg>
                     </compilerArgs>
                 </configuration>

src/main/java/com/thealgorithms/ciphers/RSA.java

@@ -47,7 +47,7 @@ public synchronized BigInteger decrypt(BigInteger encryptedMessage) {
     /**
      * Generate a new public and private key set.
      */
-    public synchronized void generateKeys(int bits) {
+    public final synchronized void generateKeys(int bits) {
         SecureRandom r = new SecureRandom();
         BigInteger p = new BigInteger(bits / 2, 100, r);
         BigInteger q = new BigInteger(bits / 2, 100, r);

src/main/java/com/thealgorithms/datastructures/heaps/MaxHeap.java

@@ -91,7 +91,7 @@ private HeapElement extractMax() {
     }
 
     @Override
-    public void insertElement(HeapElement element) {
+    public final void insertElement(HeapElement element) {
         maxHeap.add(element);
         toggleUp(maxHeap.size());
     }

src/main/java/com/thealgorithms/datastructures/heaps/MinHeap.java

@@ -85,7 +85,7 @@ private HeapElement extractMin() {
     }
 
     @Override
-    public void insertElement(HeapElement element) {
+    public final void insertElement(HeapElement element) {
         minHeap.add(element);
         toggleUp(minHeap.size());
     }

src/main/java/com/thealgorithms/datastructures/lists/DoublyLinkedList.java

@@ -13,7 +13,7 @@
  *
  * @author Unknown
  */
-public class DoublyLinkedList {
+public final class DoublyLinkedList {
 
     /**
      * Head refers to the front of the list

src/main/java/com/thealgorithms/datastructures/trees/SegmentTree.java

@@ -19,7 +19,7 @@ public SegmentTree(int n, int[] arr) {
     }
 
     /* A function which will create the segment tree*/
-    public int constructTree(int[] arr, int start, int end, int index) {
+    public final int constructTree(int[] arr, int start, int end, int index) {
         if (start == end) {
             this.seg_t[index] = arr[start];
             return arr[start];