TestNG.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://TestNG.org/TestNG-1.0.dtd">
<suite name="TestSuite" parallel="tests" thread-count="4">
   <test name="ChromeBrowserTest">
       <parameter name="browser" value="Chrome"/>
       <classes>
           <class name="com.pages.DemoTest1">
           </class>
       </classes>
   </test>
   <test name="FirefoxBrowserTest">
       <parameter name="browser" value="Firefox" />
       <classes>
           <class name="com.pages.DemoTest1">
           </class>
       </classes>
   </test>

   <test name="EdgeBrowserTest">
       <parameter name="browser" value="Edge" />
       <classes>
           <class name="com.pages.DemoTest1">
           </class>
       </classes>
   </test>
</suite>