results := c.CheckExpression(ctx, v.Expression)
		if len(results) != 0 {
			warnings = append(warnings, v1.ExpressionWarning{
				FieldRef: fieldRef.Index(i).Child("expression").String(),
				Warning:  results.String(),
			})
		}
		// Note that MessageExpression is optional
		if v.MessageExpression == "" {
			continue
		}
		results = c.CheckExpression(ctx, v.MessageExpression)