Method cancel

http/unstable_formdata_decoder_stream.ts:236–244

()

            }
          },
          async cancel() {
            do {
              buffer = (await reader.read()).value?.value;
              if (buffer == undefined) {
                return error(new SyntaxError("Unexpected EOF"));
              }
            } while (!boundary.every((x, i) => x === buffer![i]));
            releaseLock();
          },
        }),
      };
      if (entry.name === "_charset_") {