Missing isMaskOutline property in FigmaPlugin API

In Figma API there exists isMaskOutline property on Frame like objects


isMaskOutlineBoolean default: false
Does this mask ignore fill style (like gradients) and effects?

But am missing this data in Figma Plugin API:

Can found only isMask but isMaskOutline seems to be missing.
Is my observation correct, or is this field renamed or accessible in some different way?

Thank you for response

To be clear what it represents in Figma:

isMaskOutline should represent this checkBox in Mask => Use shape outlines