private static bool IsEventHandlerAssignLhs(CSharpSyntaxNode syntax) { var assignmentExpressionSyntax = syntax.GetAncestor <AssignmentExpressionSyntax>(); return(assignmentExpressionSyntax != null && assignmentExpressionSyntax.IsKind(CSSyntaxKind.AddAssignmentExpression, CSSyntaxKind.SubtractAssignmentExpression) && assignmentExpressionSyntax.Left.DescendantNodes().Contains(syntax)); }