The animation description.
Animation caption.
Optional
has_True, if the animation preview must be covered by a spoiler animation.
Optional
is_True, if the animation thumbnail must be blurred and the animation must be shown only while tapped.
Optional
show_True, if the caption must be shown above the animation; otherwise, the caption must be shown below the animation.
An animation message (GIF-style). Subtype of MessageContent.