code: @JsonIgnore
      public void encodeAndSetContent(String content) {
          encodeAndSetContent(content != null ? content.getBytes() : null);
      }
docs: Encodes the provided String using Base64 and sets it as the content. The encoding
  property of this instance will be set to base64.
  
  @param content the String content to encode and set as the base64 encoded String content