shouldSignHeader

A predicate to control which headers are a part of the canonical request. Note that skipping auth-required headers will result in an unusable signature. Headers injected by the signing process cannot be skipped.

This function does not override the internal check function (e.g., for x-amzn-trace-id, user-agent, etc.) but rather supplements it. In particular, a header will get signed if and only if it returns true to both the internal check and this function (if defined).

The default predicate signs all headers (i.e., _ -> true).