CalloutCallout component for displaying informational messages with different variants. heading is an optional string representing the heading of the callout. When set to None, a default heading based on the variant is used. children is a list of TyXML elements representing the content of the callout.
val to_string : t -> stringval to_icon : t -> Icon.callout_variantval default_heading : t -> stringval render : t -> [> Html_types.div ] Tyxml.Html.elt