es6 class function

src/solidity/types/Enum.js

@@ -13,15 +13,14 @@ class Enum extends ValueType {
     super(1, storageBytes, 'enum')
     this.enumDef = enumDef
   }
-}
 
-Enum.prototype.decodeFromStorage = function (location, storageContent) {
+  decodeFromStorage (location, storageContent) {
     var value = util.extractHexValue(location, storageContent, this.storageBytes)
     value = parseInt(value, 16)
     return output(value, this.enumDef)
-}
+  }
 
-Enum.prototype.decodeFromStack = function (stackDepth, stack, memory) {
+  decodeFromStack (stackDepth, stack, memory) {
     var defaultValue = 0
     if (stack.length - 1 < stackDepth) {
       defaultValue = 0
@@ -30,13 +29,14 @@ Enum.prototype.decodeFromStack = function (stackDepth, stack, memory) {
       defaultValue = parseInt(defaultValue, 16)
     }
     return output(defaultValue, this.enumDef)
-}
+  }
 
-Enum.prototype.decodeFromMemory = function (offset, memory) {
+  decodeFromMemory (offset, memory) {
     var value = memory.substr(offset, 64)
     value = util.extractHexByteSlice(value, this.storageBytes, 0)
     value = parseInt(value, 16)
     return output(value, this.enumDef)
+  }
 }
 
 function output (value, enumDef) {