list containing the objects to plot, made as a call to the
Plot function
takeFromPlotObj
Logical. Should the data come from the argument passed
into Plot (TRUE), or from the (.spadesEnv)
(FALSE).
Details
Because the Plot function can use the global environment as a source of
objects to plot, not just the call itself, this function identifies where
the data for the grob should come from, the current call or the global
environment.