refactoring: modified modem.java (#1952)

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Hayes.java

@@ -29,7 +29,7 @@ import lombok.extern.slf4j.Slf4j;
  * Hayes class implements its accept method.
  */
 @Slf4j
-public class Hayes extends Modem {
+public class Hayes implements Modem {
 
   /**
    * Accepts all visitors but honors only HayesVisitor.

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Modem.java

@@ -24,8 +24,9 @@
 package com.iluwatar.acyclicvisitor;
 
 /**
- * Modem abstract class.
+ * //Modem abstract class.
+ * converted to an interface
  */
-public abstract class Modem {
+public interface Modem {
-  public abstract void accept(ModemVisitor modemVisitor);
+   void accept(ModemVisitor modemVisitor);
 }

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Zoom.java

@@ -29,7 +29,7 @@ import lombok.extern.slf4j.Slf4j;
  * Zoom class implements its accept method.
  */
 @Slf4j
-public class Zoom extends Modem {
+public class Zoom implements Modem {
 
   /**
    * Accepts all visitors but honors only ZoomVisitor.