     }
 
     /**
-     Converts given amount from a `base unit` to the `current unit`.
-     
-     - parameter amount: `amount` in a `base unit`.
-     
-     - returns: `amount` converted to the `current unit`.
+     Converts given `amount` from `base unit` to `this unit`.
+     
+     - parameter amount: `amount` in `base unit`.
+     
+     - returns: `amount` converted to `this unit`.
      
      - author: Michal Konturek
      */

extension Unit: UnitConvertible {

    /**
     Converts `amount` from a `current unit` to a `destination unit`.
     
     - parameter amount: given `amount` in the `current unit`.
     - parameter to: given `destination unit`.
     
     - returns: `amount` converted to `destination unit`.
     

    func convert(amount: NSNumber, to: Unit) -> NSNumber
    
    /**
     Converts `amount` from `source unit` to `this unit`.
     
     - parameter amount: `amount` in `source unit`.
     - parameter from: `source unit`.
     
     - returns: `amount` converted from `source unit` to `this unit`.
     
     - author: Michal Konturek
     */
    func convert(amount: NSNumber, from: Unit) -> NSNumber
    
    /**
     Converts `amount` from `source unit` to `destination unit`.
     
     - parameter amount: `amount` in `source unit`.
     - parameter from: `source unit`.
     - parameter to: `destination unit`.
     
     - returns: `amount` converted from `source unit` to `destination unit`.
     
     - author: Michal Konturek
     */
    func convert(amount: NSNumber, from: Unit, to: Unit) -> NSNumber
    
    /**
     Returns `true` if `this unit` is convertible with `other unit`.
     
     - parameter with: `other unit` to compare with.
     
     - author: Michal Konturek
     */
