         }
         aCoder.encode(self.converter, forKey:"converter")
     }
-
+    
     open override func isEqual(_ object: Any?) -> Bool {
         guard let other = object as? Dimension else {
             return false
         }
-
-        if self === other {
-            return true
-        }
-
+        
+        if self === other {
+            return true
+        }
+        
         return super.isEqual(object) && self.converter == other.converter
     }
 }

    /*
     Base unit - newtonsPerMetersSquared (equivalent to 1 pascal)
     */

    public required init(symbol: String) {
        fatalError("init(symbol:) has not been implemented")
    }

    public required init(symbol: String, converter: UnitConverter) {
        super.init(symbol: symbol, converter: converter)
    }
    
    private struct Symbol {
        static let newtonsPerMetersSquared  = "N/m²"

        self.init(symbol: symbol, converter: UnitConverterLinear(coefficient: coefficient))
    }
    
    open class var newtonsPerMetersSquared: UnitPressure {
        get {
            return UnitPressure(symbol: Symbol.newtonsPerMetersSquared, coefficient: Coefficient.newtonsPerMetersSquared)
