<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def process_file(self, path, dryrun):
 """ Add header to all files. """

        if dryrun:
            return path

        # get file's current header
        with open(path, "r") as infile:
            head = infile.read(len(self.__header))

        # normalize line breaks
        if self.__normalize_br:
            head = head.replace("\r\n", "\n")

        # already contain header? skip
        if head == self.__header:
            return path

        # add header to file
        self.push_header(path)

        # return processed file
        return path