Access miniatures in text areas via the API

Sometimes the need arises to manipulate a text area using IronPython to change specific parts of the text area.

However, when changing the html content of a text area using IronPython you often destroy the Spotfire dynamic contents (calculated values, labels, and so on). An elegant way to go around this problem would be to access these mininatures instead. For example, one could change the WhereClauseExpression of a Calculated value based on some other action in the document.

In order to do that, we need a way to access these miniatures from the API. Something like
text_area = some_visual.As[HtmlTextArea]()

text_area.Miniatures # List of CalculatedValues in the text area.