public void IsExtensionExpression() { var extensionExpression = new TestExtensionExpression(Expression.Constant(0)); Assert.That(ExpressionTreeVisitor.IsExtensionExpression(extensionExpression), Is.True); var standardExpression = Expression.Constant(0); Assert.That(ExpressionTreeVisitor.IsExtensionExpression(standardExpression), Is.False); var unknownExpression = new UnknownExpression(typeof(int)); Assert.That(ExpressionTreeVisitor.IsExtensionExpression(unknownExpression), Is.False); var querySourceReferenceExpression = new QuerySourceReferenceExpression(ExpressionHelper.CreateMainFromClause_Int()); Assert.That(ExpressionTreeVisitor.IsExtensionExpression(querySourceReferenceExpression), Is.False); var subQueryExpression = new SubQueryExpression(ExpressionHelper.CreateQueryModel <Cook> ()); Assert.That(ExpressionTreeVisitor.IsExtensionExpression(subQueryExpression), Is.False); }