for issue: iluwatar#584

Pull request description
It.s seems the equal() method in the abstract class isn't designed properly and I make some change in these abstract classes and their subclasses.
for issue: iluwatar#584

Author: jasciiz

prototype/src/main/java/com/iluwatar/prototype/Beast.java

@@ -38,14 +38,6 @@ public Beast(Beast source) {
   public abstract Beast copy();
 
   @Override
-  public boolean equals(Object obj) {
-    if (this == obj) {
-      return true;
-    }
-    if (obj == null) {
-      return false;
-    }
-    return getClass() == obj.getClass();
-  }
+  public abstract boolean equals(Object obj);
 
 }

prototype/src/main/java/com/iluwatar/prototype/ElfBeast.java

@@ -54,7 +54,7 @@ public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     }
-    if (!super.equals(obj)) {
+    if (obj ==null) {
       return false;
     }
     if (getClass() != obj.getClass()) {

prototype/src/main/java/com/iluwatar/prototype/ElfMage.java

@@ -54,7 +54,7 @@ public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     }
-    if (!super.equals(obj)) {
+    if (obj ==null) {
       return false;
     }
     if (getClass() != obj.getClass()) {

prototype/src/main/java/com/iluwatar/prototype/ElfWarlord.java

@@ -54,7 +54,7 @@ public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     }
-    if (!super.equals(obj)) {
+    if (obj ==null) {
       return false;
     }
     if (getClass() != obj.getClass()) {

prototype/src/main/java/com/iluwatar/prototype/Mage.java

@@ -38,14 +38,6 @@ public Mage(Mage source) {
   public abstract Mage copy();
 
   @Override
-  public boolean equals(Object obj) {
-    if (this == obj) {
-      return true;
-    }
-    if (obj == null) {
-      return false;
-    }
-    return getClass() == obj.getClass();
-  }
+  public abstract boolean equals(Object obj);
 
 }

prototype/src/main/java/com/iluwatar/prototype/OrcBeast.java

@@ -54,7 +54,7 @@ public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     }
-    if (!super.equals(obj)) {
+    if (obj ==null) {
       return false;
     }
     if (getClass() != obj.getClass()) {

prototype/src/main/java/com/iluwatar/prototype/OrcMage.java

@@ -54,7 +54,7 @@ public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     }
-    if (!super.equals(obj)) {
+    if (obj ==null) {
       return false;
     }
     if (getClass() != obj.getClass()) {

prototype/src/main/java/com/iluwatar/prototype/OrcWarlord.java

@@ -54,7 +54,7 @@ public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     }
-    if (!super.equals(obj)) {
+    if (obj ==null) {
       return false;
     }
     if (getClass() != obj.getClass()) {

prototype/src/main/java/com/iluwatar/prototype/Warlord.java

@@ -38,14 +38,6 @@ public Warlord(Warlord source) {
   public abstract Warlord copy();
 
   @Override
-  public boolean equals(Object obj) {
-    if (this == obj) {
-      return true;
-    }
-    if (obj == null) {
-      return false;
-    }
-    return getClass() == obj.getClass();
-  }
+  public abstract boolean equals(Object obj);
 
 }