matttproud/golang_instrumentation — pull request #4 by kesselborn (2013-01-03 17:53:13+00:00)
Title: Remove explicit WriteHeader call to have correct content type

According to the documentation:

// WriteHeader sends an HTTP response header with status code.
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
// Thus explicit calls to WriteHeader are mainly used to
// send error codes.

and

// Header returns the header map that will be sent by WriteHeader.
// Changing the header after a call to WriteHeader (or Write) has
// no effect.

so calling `w.Header().Set(contentType, jsonContentType)` after calling
`w.WriteHeader` does not set the content type -- the call can be removed
though as it always set `http.StatusOK` which will be done anyways