// out the meta-data file, and register emitCounterData as an exit
// hook.
//
// If 'istest' is true (indicating that the program in question is a
// Go test binary), then we tentatively queue up both emitMetaData and
// emitCounterData as exit hooks. In the normal case (e.g. regular "go
// test -cover" run) the testmain.go boilerplate will run at the end

// The Reader will return an [ErrChecksum] when [Reader.Read]
// reaches the end of the uncompressed data if it does not
// have the expected length or checksum. Clients should treat data
// returned by [Reader.Read] as tentative until they receive the [io.EOF]
// marking the end of the data.
type Reader struct {
	Header       // valid after NewReader or Reader.Reset
	r            flate.Reader
	decompressor io.ReadCloser