prview: check that the data being sent to the prview writer is of the right type.
prview: check that the data being sent to the prview writer is of the right type.

SasView/sasview,lewisodriscoll/sasview,lewisodriscoll/sasview,lewisodriscoll/sasview,SasView/sasview,SasView/sasview,SasView/sasview,SasView/sasview,lewisodriscoll/sasview,SasView/sasview,lewisodriscoll/sasview