instance method valid_const?

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 270
      def valid_const?
        if app_const =~ /^\d/
          raise Error, "Invalid application name #{app_name}. Please give a name which does not start with numbers."
        elsif RESERVED_NAMES.include?(app_name)
          raise Error, "Invalid application name #{app_name}. Please give a name which does not match one of the reserved rails words."
        elsif Object.const_defined?(app_const_base)
          raise Error, "Invalid application name #{app_name}, constant #{app_const_base} is already in use. Please choose another application name."
        end
      end