code: function isType(what, typeName) {
      "use strict";
      if (typeof typeName !== "string" || !typeName) {
          throw new CasperError("You must pass isType() a typeName string");
      }
      return betterTypeOf(what).toLowerCase() === typeName.toLowerCase();
  }
docs: Shorthands for checking if a value is of the given type. Can check for
  arrays.
  
  @param  mixed   what      The value to check
  @param  String  typeName  The type name ("string", "number", "function", etc.)
  @return Boolean