npm and error messages

node_modules/buffer-xor/inplace.js

@@ -0,0 +1,9 @@
+module.exports = function xorInplace (a, b) {
+  var length = Math.min(a.length, b.length)
+
+  for (var i = 0; i < length; ++i) {
+    a[i] = a[i] ^ b[i]
+  }
+
+  return a.slice(0, length)
+}