code: private void encodeThis() throws IOException {
          if (certPolicies == null || certPolicies.isEmpty()) {
              this.extensionValue = null;
          } else {
              DerOutputStream os = new DerOutputStream();
              DerOutputStream tmp = new DerOutputStream();
  
              for (PolicyInformation info : certPolicies) {
                  info.encode(tmp);
              }
  
              os.write(DerValue.tag_Sequence, tmp);
              this.extensionValue = os.toByteArray();
          }
      }
docs: Encode this extension value.