How to get/set textDocument.fontSize at character/word level using after effects script

Following is the text in scripting guide documentation

TextDocument fontSize attribute

textDocument.fontSize

NOTE: If the text layer has different font size settings for each character, this attribute returns the setting for the

first character. Also, if you change the value, it resets all characters in the text layer to the specified setting.

But there its not specifying way to get character level fontSize option. Is there any way or workaround to set / get character level fontSize

Thanks