namedranges in google docs – get elements then get text from them

As I understand from the documentation, a namedrange is an object that can be given a name and each range comprises one or more elements (e.g. text element). Once I have created a namedrange, I can then get all range objects of that namerange within the document using getNamedRanges() and then on each range object I can then use getRangeElements().

The following script uses the element returned by insertText() to create a namedrange 'element1' in google docs (ultimately, I will have multiple namedranges most with a unique name). Using getNamedRanges() I get back all namedranges in the document and then getRangeElements() to access each element of each of those namedranges. This is what I hope the following script does (simplified with just one namedrange and one text element in it).

  var document = DocumentApp.getActiveDocument();  var cursor = document.getCursor();  var element = cursor.insertText('1st element');  var rangeBuilder = document.newRange();  rangeBuilder.addElement(element);  document.addNamedRange('element1', rangeBuilder.build());  var ranges = document.getNamedRanges();  var rangeElements = [];  var rangeTexts = [];  for (var i = 0; i < ranges.length; i++) {    rangeElements.push(ranges[i].getRangeElements());    for (var j = 0; j < rangeElements.length; j++) {      rangeTexts.push(rangeElements[j].getText());    }  }

However, I get the error 'TypeError: ranges[i].getRangeElements is not a function'.

ranges is an array of objects and so range[i]is one range object on which I should be able to use the range method getRangeElements() (and because these range elements comprise text elements, I should then be able to use getText() on each of them).

All examples in the documentation I come across demonstrate the use of ranges within the user's selection rather than, as here, wrapping a range around the element that has been newly inserted. Perhaps the technique is different in that case.

Presumably I get the error because my understanding of name ranges is incorrect so where have I gone wrong? (Note, this is google docs not google sheets.)