code: function validateMethods() {
    xml2js.METHODS = _.pick(xml2js.METHODS, function(methodSpec, methodName) {
      return hasValidTypes(methodSpec, methodName);
    });
    _.each(xml2js.CLASSES, function(classSpec, className) {
      var valid = _.pick(classSpec.methods, function(methodSpec, methodName) {
        return hasValidTypes(methodSpec, className + '.' + methodName, className);
      });
      if (xml2js.opts.strict) {
        xml2js.CLASSES[className].methods = valid;
      }
    });
  }
docs: make sure methods have valid types, otherwise warn (& don't include if strict)