code: public static boolean isMultiPartForm(@CheckForNull String contentType) {
          if (contentType == null) {
              return false;
          }
  
          String[] parts = contentType.split(";");
          return ArrayUtils.contains(parts, "multipart/form-data");
      }
docs: Checks a Content-Type string to assert if it is "multipart/form-data".
  
  @param contentType Content-Type string.
  @return {@code true} if the content type is "multipart/form-data", otherwise {@code false}.
  @since 1.620