code: @Nonnull
    public FineUploader5DeleteFile addParam (@Nonnull @Nonempty final String sKey, @Nonnull final String sValue)
    {
      ValueEnforcer.notEmpty (sKey, "Key");
      ValueEnforcer.notNull (sValue, "Value");
  
      m_aDeleteFileParams.put (sKey, sValue);
      return this;
    }
docs: Any additional parameters to attach to delete file requests.
  
  @param sKey
  Parameter name
  @param sValue
  Parameter value
  @return this