"\code{gvis}" and "\code{list}".   
An object of class "\code{gvis}" is a list containing at least the
following components:
\describe{
\item{\code{type}}{Google visualisation type}
\item{\code{chartid}}{character id of the chart object. Unique chart
ids are required to place several charts on the same page.
}
\item{\code{html}}{a list with the building blocks for a page
\describe{
\item{\code{header}}{a character string of a html page header:
\code{...},}
\item{\code{chart}}{a named character vector of the chart's building blocks:
\describe{
\item{\code{jsHeader}}{Opening \code{}.
}
\item{\code{jsChart}}{Call of the \code{jsDisplayChart} function.
}
\item{\code{divChart}}{\code{<div>} container to embed the chart
into the page.
}
}   
}
\item{\code{caption}}{character string of a standard caption,
including data name and chart id.
}  
\item{\code{footer}}{character string of a html page footer:
\code{...}, including the used R and googleVis version
and link to Google's Terms of Use.}
}}
}
