def valid_grammar?
      return true unless options.key?(:search_grammar)
      return false unless File.exist?(options[:search_grammar])
      search = FoodCritic::Chef::Search.new
      search.create_parser([options[:search_grammar]])
      search.parser?
    end
def valid_grammar?
      return true unless options.key?(:search_grammar)
      return false unless File.exist?(options[:search_grammar])
      search = FoodCritic::Chef::Search.new
      search.create_parser([options[:search_grammar]])
      search.parser?
    end
Is the search grammar specified valid?

 @return [Boolean] True if the grammar has not been provided or can be
   loaded.