Push the header to a given filename
        :param filename: the file path to push into.

def push_header(self, filename):
        """
        Push the header to a given filename
        :param filename: the file path to push into.
        """
        # open file and read it all
        with open(filename, "r") as infile:
            content = infile.read()

        # push header
        content = self.__header + content

        # re-write file with the header
        with open(filename, "w") as outfile:
            outfile.write(content)