es6 class function

src/solidity/types/Int.js

@@ -6,23 +6,23 @@ class Int extends ValueType {
   constructor (storageBytes) {
     super(1, storageBytes, 'int')
   }
-}
 
-Int.prototype.decodeFromStorage = function (location, storageContent) {
+  decodeFromStorage (location, storageContent) {
     return util.decodeInt(location, storageContent, this.storageBytes, true)
-}
+  }
 
-Int.prototype.decodeFromStack = function (stackDepth, stack, memory) {
+  decodeFromStack (stackDepth, stack, memory) {
     if (stackDepth >= stack.length) {
       return '0'
     } else {
       return util.decodeIntFromHex(stack[stack.length - 1 - stackDepth].replace('0x', ''), 32, true)
     }
-}
+  }
 
-Int.prototype.decodeFromMemory = function (offset, memory) {
+  decodeFromMemory (offset, memory) {
     var value = memory.substr(offset, 64)
     return util.decodeIntFromHex(value, 32, true)
+  }
 }
 
 module.exports = Int