Write out the header

def _write_header(self):
        """Write out the header"""
        for line in self.header.lines:
            print(line.serialize(), file=self.stream)
        if self.header.samples.names:
            print(
                "\t".join(list(parser.REQUIRE_SAMPLE_HEADER) + self.header.samples.names),
                file=self.stream,
            )
        else:
            print("\t".join(parser.REQUIRE_NO_SAMPLE_HEADER), file=self.stream)