code: function () {
          var contentLength = this.headers.get(CONTENT_LENGTH),
              requestTarget = this.url.getPathWithQuery(),
              bodyString,
              sizeInfo = {
                  body: 0,
                  header: 0,
                  total: 0,
                  source: SIZE_SOURCE.computed
              };
  
          // if 'Content-Length' header is present, we take body as declared by
          // the client(postman-request or user-defined). else we need to compute the same.
          if (contentLength && util.isNumeric(contentLength)) {
              sizeInfo.body = parseInt(contentLength, 10);
              sizeInfo.source = SIZE_SOURCE.contentLength;
          }
          // otherwise, if body is defined, we calculate the length of the body
          else if (this.body) {
              // @note body.toString() returns E for formdata or file mode
              bodyString = this.body.toString();
              sizeInfo.body = supportsBuffer ? Buffer.byteLength(bodyString) : bodyString.length;
          }
  
          // https://tools.ietf.org/html/rfc7230#section-3
          // HTTP-message   = start-line (request-line / status-line)
          //                  *( header-field CRLF )
          //                  CRLF
          //                  [ message-body ]
          // request-line = method SP request-target SP HTTP-version CRLF
          sizeInfo.header = (this.method + SP + requestTarget + SP + HTTP_X_X + CRLF + CRLF).length +
              this.headers.contentSize();
  
          // compute the approximate total body size by adding size of header and body
          sizeInfo.total = (sizeInfo.body || 0) + (sizeInfo.header || 0);
          return sizeInfo;
      }
docs: Get the request size by computing the headers and body or using the
  actual content length header once the request is sent.
  
  @returns {Object}