Destroys the HTML panel
Hides the panel if it's visible.
Changes the panel height.
Shows the panel if it's hidden.
This promise resolves when the "DOMContentLoaded" event fires on the ifram's window.
The HTML Panel iframe's https://developer.mozilla.org/en-US/docs/Web/API/Window object
This promise resolves when the "load" event fires on the ifram's window.
trueif the panel is visible,
falseif it's hidden or destroyed
If you don't need to change the height after the panel is created, you can pass it as an option to the