title: method does not override or implement a method from a supertype
body: <p>I am trying to override the abstract method of the class "NamespacePrefixMapper" to provide my custom name space for the xml attribute . But it keeps giving the following error message .</p>
  
  <pre><code>.c.compile:
     [javac] Compiling 1 source file to C:\isp_development\target\dmc_ac_efulfilment\release\lib
     [javac] C:\isp_development\source\dmc_ac_efulfilment\javasource\de\dmc\enfinity\adapter\efulfilment\client\JustForTest.java:3: error: package com.sun.xml.internal.bind.marshaller does not exist
     [javac] import com.sun.xml.internal.bind.marshaller.NamespacePrefixMapper;
     [javac]                                            ^
     [javac] C:\isp_development\source\dmc_ac_efulfilment\javasource\de\dmc\enfinity\adapter\efulfilment\client\JustForTest.java:5: error: cannot find symbol
     [javac] public class JustForTest extends NamespacePrefixMapper {
     [javac]                                  ^
     [javac]   symbol: class NamespacePrefixMapper
     [javac] C:\isp_development\source\dmc_ac_efulfilment\javasource\de\dmc\enfinity\adapter\efulfilment\client\JustForTest.java:7: error: method does not override or implement a method from a supertype
     [javac]     @Override
     [javac]     ^
     [javac] 3 errors
  </code></pre>
  
  <p>Below is the method code i am trying to overide. </p>
  
  <pre><code> @Override
      public String getPreferredPrefix(String namespaceUri, String suggestion, boolean requirePrefix) {
      namespaceUri = "http://base.google.com/ns/1.0";
      suggestion="g";
      requirePrefix=true;
      return suggestion;
      }
  </code></pre>
  
  <p>What cloud be the reason. Help will be greatly appreciated. </p>