def attr_configurable_arr *args, &block
      trans = attr_configurable_wrap lambda { |v| Array(v) }, block
      attr_configurable(*args, &trans)
    end
def attr_configurable_arr *args, &block
      trans = attr_configurable_wrap lambda { |v| Array(v) }, block
      attr_configurable(*args, &trans)
    end
Creates a group readable and writeable attributes that can be set
 by a URI query parameter sharing the same name, a property of a URI or
 a default value. The value of this attribute will be transformed by
 invoking the given block, if one has been provided. If the attributes
 created by this method are assigned a value that is not an `Array`, the
 value will be wrapped in an array.