 
 extension NSNumber {
 
+    /**
+     Returns instance converted as century quantity.
+     
+     - author: Michal Konturek
+     */
     public func century() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.century)
     }
 
+    /**
+     Returns instance converted as decade quantity.
+     
+     - author: Michal Konturek
+     */
     public func decade() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.decade)
     }
 
+    /**
+     Returns instance converted as year quantity.
+     
+     - author: Michal Konturek
+     */
     public func year() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.year)
     }
 
+    /**
+     Returns instance converted as month quantity.
+     
+     - author: Michal Konturek
+     */
     public func month() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.month)
     }
 
+    /**
+     Returns instance converted as week quantity.
+     
+     - author: Michal Konturek
+     */
     public func week() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.week)
     }
 
+    /**
+     Returns instance converted as day quantity.
+     
+     - author: Michal Konturek
+     */
     public func day() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.day)
     }
 
+    /**
+     Returns instance converted as hour quantity.
+     
+     - author: Michal Konturek
+     */
     public func hour() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.hour)
     }
 
+    /**
+     Returns instance converted as minute quantity.
+     
+     - author: Michal Konturek
+     */
     public func minute() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.minute)
     }
 
+    /**
+     Returns instance converted as second quantity.
+     
+     - author: Michal Konturek
+     */
     public func second() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.second)
     }
 
+    /**
+     Returns instance converted as millisecond quantity.
+     
+     - author: Michal Konturek
+     */
     public func millisecond() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.millisecond)
     }
 
+    /**
+     Returns instance converted as microsecond quantity.
+     
+     - author: Michal Konturek
+     */
     public func microsecond() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.microsecond)
     }
 
+    /**
+     Returns instance converted as nanosecond quantity.
+     
+     - author: Michal Konturek
+     */
     public func nanosecond() -> Quantity {
         return Quantity(amount: self, unit: TimeUnit.nanosecond)
     }

        )
    }

    public static var nanosecond: TimeUnit {
        return TimeUnit(
            name: "nanosecond",

        )
    }

    /**
     Returns week `[wk]` time unit.
     
     - author: Michal Konturek
     */
    public static var week: TimeUnit {
        return TimeUnit(
            name: "week",
