# File lib/sprockets/preprocessor.rb, line 13
    def require(source_file)
      return if source_files.include?(source_file)
      source_files << source_file
      
      source_file.each_source_line do |source_line|
        if source_line.require?
          require_from_source_line(source_line)
        elsif source_line.provide?
          provide_from_source_line(source_line)
        else
          record_source_line(source_line)
        end
      end
    end