Defining environment variables is not clear about jenkinspipelineunit HOT 1 OPEN

import com.lesfurets.jenkins.unit.BasePipelineTest 
 
class TestExampleJob extends BasePipelineTest { 
    @Override 
    @BeforeEach 
    void setUp() { 
        super.setUp() 
        // Define environment variable 
        addEnvVar('MY_ENV_VAR', '0')
        // Assigns false to a job parameter ENABLE_TEST_STAGE 
        addParam('ENABLE_TEST_STAGE', 'false')
        // Defines the previous execution status 
        binding.getVariable('currentBuild').previousBuild = [result: 'UNSTABLE'] 
        // Define Jenkins global variable
        binding.setVariable('RUN_DISPLAY_URL', 'https://jenkins.io')
    } 
 
    @Test 
    void verifyParam() { 
        assertEquals('false', binding.getVariable('params')['ENABLE_TEST_STAGE']) 
    } 
}