def validates_acceptance_of(*attribute_names)
      options = Macros.extract_options(attribute_names)
      validation_rules.add(Rule::Acceptance, attribute_names, options)
    end
def validates_acceptance_of(*attribute_names)
      options = Macros.extract_options(attribute_names)
      validation_rules.add(Rule::Acceptance, attribute_names, options)
    end
Validates that the attributes's value is in the set of accepted
 values.

 @option [Boolean] :allow_nil (true)
   true if nil is allowed, false if not allowed.

 @option [Array] :accept (["1", 1, "true", true, "t"])
   A list of accepted values.

 @example Usage
   require 'virtus'
   require 'aequitas'

   class Page
     include Virtus
     include Aequitas

     attribute :license_agreement_accepted, String
     attribute :terms_accepted, String

     validates_acceptance_of :license_agreement, :accept => "1"
     validates_acceptance_of :terms_accepted, :allow_nil => false

     # a call to valid? will return false unless:
     # license_agreement is nil or "1"
     # and
     # terms_accepted is one of ["1", 1, "true", true, "t"]
   end