java - TestNG parallel attribute has no effect on the method execution -

i trying run test methods in parallel. parallel attribute in testng xml has no effect on execution. runs same 4 possible options (methods,tests,classes,instances).i.e methods called in sequential 4 option.but need them run in parallel fashion. here understand "methods" option should work me. help?

the testng xml follows.

<!doctype suite system "http://testng.org/testng-1.0.dtd" >   <suite name="test suite" verbose="1" parallel="methods" thread-count="2">      <test name="parallel">         <classes>           <class name="com.sample.a" />         </classes>      </test>   </suite> 

and test class follow

package com.sample;  class {  @test public void abc() throws exception  {         // code here  }  @test public void xyz() throws exception  {         //some code here  }   } 

you can see link http://maven.apache.org/surefire/maven-surefire-plugin/examples/junit.html   pom             <plugin>                 <groupid>org.apache.maven.plugins</groupid>                 <artifactid>maven-surefire-plugin</artifactid>                 <version>2.9</version>                 <configuration>                     <suitexmlfiles>                         <suitexmlfile>${testng.xml}</suitexmlfile>                     </suitexmlfiles>                 </configuration>             </plugin>