public function testBadAPIKey()
 {
     $this->mailapi = new MAILAPI_Client('invalid_api_key');
     $response = $this->mailapi->ping();
     $this->assertTrue(MAILAPI_Error::isError($response));
     $this->assertEquals(11003, $response->getErrorCode());
 }
<?php

include "../MAILAPI_Client.php";
// Make sure we have an api key
if (getenv('MAILAPI_KEY') == null) {
    exit('Set setenv("MAILAPI_KEY") to use this example');
}
// Make sure we have an email address
if (getenv('MAILAPI_TEST_EMAIL') == null) {
    exit('Set setenv("MAILAPI_TEST_EMAIL") to use this example');
}
// Create our API object
$mailapi = new MAILAPI_Client(getenv('MAILAPI_KEY'));
// Unsubscribe list member
$response = $mailapi->unsubMember(getenv('MAILAPI_TEST_EMAIL'));
// Evaluate response
if (MAILAPI_Error::isError($response)) {
    echo "Error \n";
    echo "Code: " . $response->getErrorCode() . "\n";
    echo "Message: " . $response->getErrorMessage() . "\n";
} else {
    echo "Success\n";
}