code: @Deprecated
      public static Part<InputStream> file(String name, String fileName, InputStream in) {
          return new Part<>(name, fileName, in, CONTENT_TYPE_BINARY, null, (body, out, charset) -> {
              try (InputStream bin = body) {
                  InputStreams.transferTo(bin, out);
              }
          });
      }
docs: Create a file multi-part field, from InputStream.
  This return a part equivalent to &lt;input type="file" /&gt; field in multi part form.
  
  @deprecated Http body may be send multi times(because of redirect or other reasons), use {@link Part#file(String, String, InputStreamSupplier)} instead.