dm_id = mkDefaultMethodId sel_id dm_name
local_dm_type = instantiateMethod clas sel_id (mkTyVarTys tyvars)
local_dm_id = mkLocalId local_dm_name local_dm_type
dm_id = mkDefaultMethodId sel_id dm_name
local_dm_type = instantiateMethod clas sel_id (mkTyVarTys tyvars)
local_dm_id = mkLocalId local_dm_name local_dm_type