    # File lib/rbot/messagemapper.rb, line 599
        def requirements_for(name)
          name = name.to_s.sub(/^\*/,"").intern if (/^\*/ =~ name.inspect)
          presence = (@defaults.key?(name) && @defaults[name].nil?)
          requirement = case @requirements[name]
            when nil then nil
            when Regexp then "match #{@requirements[name].inspect}"
            else "be equal to #{@requirements[name].inspect}"
          end
          if presence && requirement then "#{name} must be present and #{requirement}"
          elsif presence || requirement then "#{name} must #{requirement || 'be present'}"
          else "#{name} has no requirements"
          end
        end