This function returns 0 if it succeeds, or one of the following
negative error codes:
- :macro:`NGHTTP2_ERR_NOMEM`
+ :macro:`nghttp2_error.NGHTTP2_ERR_NOMEM`
Out of memory.
- :macro:`NGHTTP2_ERR_INVALID_ARGUMENT`
+ :macro:`nghttp2_error.NGHTTP2_ERR_INVALID_ARGUMENT`
The *settings_payload* is badly formed.
- :macro:`NGHTTP2_ERR_PROTO`
+ :macro:`nghttp2_error.NGHTTP2_ERR_PROTO`
The stream ID 1 is already used or closed; or is not available.