code: public void distrustOmemoIdentity(OmemoDevice device, OmemoFingerprint fingerprint) {
          if (trustCallback == null) {
              throw new IllegalStateException("No TrustCallback set.");
          }
  
          trustCallback.setTrust(device, fingerprint, TrustState.untrusted);
      }
docs: Distrust the fingerprint/OmemoDevice tuple.
  The fingerprint must be the lowercase, hexadecimal fingerprint of the identityKey of the device and must
  be of length 64.
  @param device device
  @param fingerprint fingerprint