Cover that SystemNodeProvider::getNode returns false when it doesn't find node

tests/src/Provider/Node/SystemNodeProviderTest.php

@@ -71,6 +71,20 @@ class SystemNodeProviderTest extends TestCase
         $this->assertEquals('AABBCCDDEEFF', $node);
     }
 
+    public function testGetNodeReturnsFalseWhenNodeIsNotFound()
+    {
+        $provider = $this->getMockBuilder('Ramsey\Uuid\Provider\Node\SystemNodeProvider')
+            ->setMethods(['getIfconfig'])
+            ->getMock();
+
+        $provider->expects($this->once())
+            ->method('getIfconfig')
+            ->willReturn('some string that does not match the mac address');
+
+        $node = $provider->getNode();
+        $this->assertFalse($node);
+    }
+
     public function testGetNodeWillNotExecuteSystemCallIfFailedFirstTime()
     {
         $provider = $this->getMockBuilder('Ramsey\Uuid\Provider\Node\SystemNodeProvider')