ol><li role=none aria-label="Before you begin"><a href=#before-you-begin>Before you begin</a><li role=none aria-label="Output-producing adapters"><a href=#output-producing-adapters>Output-producing adapters</a><li role=none aria-label="Request header operations"><a href=#request-header-operations>Request header operations</a><li role=none aria-label=Cleanup><a href=#cleanup>Cleanup</a><li role=none aria-label="See also"><a href=#see-also>See also</a></li></ol></div></nav></div></main><footer><div class=user