diff --git a/lib/plankton/plankton.d.ts b/lib/plankton/plankton.d.ts
index 1d19b5b..8414b5a 100644
--- a/lib/plankton/plankton.d.ts
+++ b/lib/plankton/plankton.d.ts
@@ -1,11 +1,11 @@
 /**
  * @author fenris
  */
-type int = number;
+declare type int = number;
 /**
  * @author fenris
  */
-type float = number;
+declare type float = number;
 declare class Buffer {
     constructor(x: string, modifier?: string);
     toString(modifier?: string): string;
@@ -19,7 +19,7 @@ declare namespace lib_plankton.base {
 /**
  * @author fenris
  */
-type type_pseudopointer<type_value> = {
+declare type type_pseudopointer<type_value> = {
     value: type_value;
 };
 /**
@@ -2002,7 +2002,7 @@ declare namespace lib_plankton.storage.memory {
         clear(): Promise<void>;
         write(key: any, value: any): Promise<boolean>;
         delete(key: any): Promise<void>;
-        read(key: any): Promise<Awaited<type_item>>;
+        read(key: any): Promise<type_item>;
         search(term: any): Promise<{
             key: string;
             preview: string;
@@ -3861,6 +3861,9 @@ declare namespace lib_plankton.pit {
     function to_ywd(pit: type_pit, { "timezone_shift": option_timezone_shift, }?: {
         timezone_shift?: int;
     }): type_ywd;
+    /**
+     */
+    function number_of_weeks(year: int): int;
     /**
      * computes the point in time for switching to central european summer time
      *
diff --git a/lib/plankton/plankton.js b/lib/plankton/plankton.js
index 11c3060..eb95740 100644
--- a/lib/plankton/plankton.js
+++ b/lib/plankton/plankton.js
@@ -2241,7 +2241,7 @@ var __generator = (this && this.__generator) || function (thisArg, body) {
     function verb(n) { return function (v) { return step([n, v]); }; }
     function step(op) {
         if (f) throw new TypeError("Generator is already executing.");
-        while (g && (g = 0, op[0] && (_ = 0)), _) try {
+        while (_) try {
             if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
             if (y = 0, t) op = [op[0] & 2, t.value];
             switch (op[0]) {
@@ -9970,12 +9970,6 @@ var lib_plankton;
          * @author fenris
          */
         class class_relation {
-            /**
-             * @author fenris
-             */
-            check(value, reference) {
-                return this.predicate(value, reference);
-            }
             /**
              * @author fenris
              */
@@ -9985,6 +9979,12 @@ var lib_plankton;
                 this.name = name;
                 this.predicate = predicate;
             }
+            /**
+             * @author fenris
+             */
+            check(value, reference) {
+                return this.predicate(value, reference);
+            }
             /**
              * @author fenris
              */
@@ -11654,6 +11654,17 @@ var lib_plankton;
             ]);
         }
         pit_1.to_ywd = to_ywd;
+        /**
+         */
+        function number_of_weeks(year) {
+            return lib_plankton.call.convey(year, [
+                x => from_ywd({ "year": (x + 1), "week": 1, "day": 6 }),
+                x => shift_week(x, -1),
+                to_ywd,
+                x => x.week,
+            ]);
+        }
+        pit_1.number_of_weeks = number_of_weeks;
         /**
          * computes the point in time for switching to central european summer time
          *
@@ -11740,7 +11751,8 @@ var lib_plankton;
                     "time": ((datetime.time === null)
                         ?
                             null
-                        : datetime_shifted.time)
+                        :
+                            datetime_shifted.time)
                 };
             }
         }