class Hashie::Trash

def self.property(property_name, options = {})

without using the :from option. It transform the property itself.
* :transform_with - Specify a lambda to be used to convert value
* :with - Specify a lambda to be used to convert value.
* :from - Specify the original key name that will be write only.
returned before a value is set on the property in a new Dash.
* :default - Specify a default value for this property, to be

Defines a property on the Trash. Options are as follows: 
def self.property(property_name, options = {})
  super
  if options[:from]
    if property_name.to_sym == options[:from].to_sym
      raise ArgumentError, "Property name (#{property_name}) and :from option must not be the same"
    end
    translations << options[:from].to_sym
    if options[:with].respond_to? :call
      class_eval do
        define_method "#{options[:from]}=" do |val|
          self[property_name.to_sym] = options[:with].call(val)
        end
      end
    else
      class_eval <<-RUBY
        def #{options[:from]}=(val)
          self[:#{property_name}] = val
        end
      RUBY
    end
  elsif options[:transform_with].respond_to? :call
    transforms[property_name.to_sym] = options[:transform_with]
  end
end