fun build_vt_tables(mclasses: Set[MClass]): Map[MClass, Array[nullable MPropDef]] do
		var tables = new HashMap[MClass, Array[nullable MPropDef]]
		for mclass in mclasses do
			var table = new Array[nullable MPropDef]
			# first, fill table from parents by reverse linearization order
			var parents = new Array[MClass]
			if mainmodule.flatten_mclass_hierarchy.has(mclass) then
				parents = mclass.in_hierarchy(mainmodule).greaters.to_a
				self.mainmodule.linearize_mclasses(parents)
			end
			for parent in parents do
				if parent == mclass then continue
				for mproperty in self.mainmodule.properties(parent) do
					if not mproperty isa MVirtualTypeProp then continue
					var color = vt_colors[mproperty]
					if table.length <= color then
						for i in [table.length .. color[ do
							table[i] = null
						end
					end
					for mpropdef in mproperty.mpropdefs do
						if mpropdef.mclassdef.mclass == parent then
							table[color] = mpropdef
						end
					end
				end
			end

			# then override with local properties
			for mproperty in self.mainmodule.properties(mclass) do
				if not mproperty isa MVirtualTypeProp then continue
				var color = vt_colors[mproperty]
				if table.length <= color then
					for i in [table.length .. color[ do
						table[i] = null
					end
				end
				for mpropdef in mproperty.mpropdefs do
					if mpropdef.mclassdef.mclass == mclass then
						table[color] = mpropdef
					end
				end
			end
			tables[mclass] = table
		end
		return tables
	end