validate_nil_attributes

# File lib/rubygems/specification_policy.rb, line 205
  def validate_nil_attributes
    nil_attributes = Gem::Specification.non_nil_attributes.select do |attrname|
      __getobj__.instance_variable_get("@#{attrname}").nil?
    end
    return if nil_attributes.empty?
    error "#{nil_attributes.join ', '} must not be nil"
  end