Method headers

github-actions/saucelabs/set-saucelabs-env.js:13450–13453

()

            if (contentType && !getHeadersList(this[kHeaders]).contains("content-type", true)) {
              this[kHeaders].append("content-type", contentType);
            }
          }
          const inputOrInitBody = initBody != null ? initBody : inputBody;
          if (inputOrInitBody != null && inputOrInitBody.source == null) {
            if (initBody != null && init.duplex == null) {
              throw new TypeError("RequestInit: duplex option is required when sending a body.");
            }