def write!
      raise MachOError, "no initial file to write to" if filename.nil?

      File.open(@filename, "wb") { |f| f.write(@raw_data) }
    end
def write!
      raise MachOError, "no initial file to write to" if filename.nil?

      File.open(@filename, "wb") { |f| f.write(@raw_data) }
    end
Write all (fat) data to the file used to initialize the instance.
 @return [void]
 @raise [MachOError] if the instance was initialized without a file
 @note Overwrites all data in the file!