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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def replace_header(self, header_text):
 """Replace pip-compile header with custom text"""

        with open(self.outfile, 'rt') as fp:
            _, body = self.split_header(fp)
        with open(self.outfile, 'wt') as fp:
            fp.write(header_text)
            fp.writelines(body)