Artifact artifact = createArtifact( "testGroup", "testArtifact", "1.0" );
pd.setArtifacts( Collections.singletonList( artifact ) );
ExpressionEvaluator ee = createExpressionEvaluator( createDefaultProject(), pd, new Properties() );
Object value = ee.evaluate( "${plugin.artifacts}" );
assertTrue( value instanceof List );
List artifacts = (List) value;