# File lib/merb-core/bootloader.rb, line 979
    def remove_classes_in_file(file, &block)
      Merb.klass_hashes.each { |x| x.protect_keys! }
      if klasses = LOADED_CLASSES.delete(file)
        klasses.each { |klass| remove_constant(klass) unless klass.to_s =~ /Router/ }
      end
      yield file if block_given?
      Merb.klass_hashes.each {|x| x.unprotect_keys!}
      nil
    end