if mwriteprop == null then
var mvisibility = new_property_visibility(modelbuilder, mclassdef, nwritable.n_visibility)
mwriteprop = new MMethod(mclassdef, writename, mvisibility)
if mwriteprop == null then
var mvisibility = new_property_visibility(modelbuilder, mclassdef, nwritable.n_visibility)
mwriteprop = new MMethod(mclassdef, writename, mvisibility)