anchor.diff:  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   %%% 
   
  -%% define client table entries record
  --record(client,
  -		{address :: inet:ip_address(),
  -		identifier = <<>> :: binary(),
  -		port :: inet:port_number(),
  -		protocol :: radius | diameter,
  -		secret :: binary(),
  -		last_modified  = {erlang:system_time(milli_seconds),
  -				erlang:unique_integer([positive])} :: tuple()}).
  -
  --record(remain_amount,
  -	{unit :: string(),
  -	amount :: integer()}).
  -
  --record(bucket,
  -		{id :: string(),
  -		name :: string(),
  -		buckt_type :: string(),
  -		remain_amount :: #remain_amount{}}).
  -
  -%% define subscriber table entries record
  --record(subscriber,
  -		{name :: binary(),
  -		password :: binary(),
  -		attributes :: radius_attributes:attributes(),
  -		buckets :: [#bucket{}],
  -		enabled = true :: boolean(),
  -		disconnect  = false :: boolean(),
  -		session_attributes = radius_attributes:new() :: [radius_attributes:attributes()],
  -		multisession = false :: boolean(),
  -		last_modified  = {erlang:system_time(milli_seconds),
  -				erlang:unique_integer([positive])} :: tuple()}).
  -
   -type product_status() :: created | aborted | cancelled
   								| active | pending_active | suspended
   								| terminate | pending_terminate.
  
positive.code: 		start_date :: pos_integer(), % ISO8601
  		termination_date :: pos_integer(), % ISO8601
  		price :: [#price{}]}).
  
negative.code: 
  %% define validity period of a product
  -type valid_period() :: daily | weekly | monthly | yealy.
  
  
  %% define client table entries record
  -record(client,
  		{address :: inet:ip_address(),
  		identifier = <<>> :: binary(),
  		port :: inet:port_number(),
  		protocol :: radius | diameter,
  		secret :: binary(),
  		last_modified  = {erlang:system_time(milli_seconds),
  				erlang:unique_integer([positive])} :: tuple()}).
  
  -record(alteration,
  		{name :: string(),
  