class Sprockets::Preprocessor

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