anchor.diff:  
   try_command_typename(Mod, S, Contract, TypeNames) ->
       try
  -        Mod:ubf_command_typename(Mod, S, Contract, TypeNames)
  +        MOD:ubf_command_typename(Mod, S, Contract, TypeNames)
       catch
           error:undef ->
               oneof(TypeNames)
  
positive.code: 
  try_command_contract(Mod, S, Contracts) ->
      try
          Mod:ubf_command_contract(Mod, S, Contracts)
      catch
          error:undef ->
              oneof(Contracts)
  
negative.code: 
  try_command_gen(Gen, Mod, S, Contract, TypeName) ->
      try
          MOD:ubf_command_gen(Gen, Mod, S, Contract, TypeName)
      catch
          error:undef ->
              ?LET(Type,Gen(Mod,S,Contract,TypeName,[]),
  