A ListImpl of PopupElement objects evaluated asynchronously by Popup.evaluateExpressions(). During the evaluation, each ExpressionPopupElement is replaced by the PopupElement returned by the Arcade expression and each placeholder is replaced by its value. If the Arcade expression returns a list of attributes to be used by the popup element, these attributes will be used by Popup.getFormattedValue(PopupField). The array is empty while Popup.evaluateExpressions() has not been executed, and is cleared if Popup.evaluateExpressions() is executed more than once. After evaluation, the order of the popup elements in the ListImpl matches the order elements present in PopupDefinition.elements and shown in the pop-up window. If an ExpressionPopupElement fails to be evaluated, then it will be skipped in the ListImpl. Use the array of PopupExpressionEvaluation returned from Popup.evaluateExpressions() to learn the cause of the error.