def write(object_file, dependent_files)
      db.transaction(false) do |store|
        store[object_file] = dependent_files
      end
    end
def write(object_file, dependent_files)
      db.transaction(false) do |store|
        store[object_file] = dependent_files
      end
    end
Saves the dependency information
 (+object_file+ => +dependent_files+).
 @return [void]