class AWS::Record::Validator

def ensure_is value_or_values, *keys
  values = Array(value_or_values)
  keys.each do |key|
    next unless options.has_key?(key)
    unless values.include?(options[key])
      valid = values.map{|v| v.is_a?(Symbol) ? ":#{v}" : v.to_s }.join(', ')
      raise ArgumentError, "expected :#{key} to be one of #{valid}"
    end
  end
end