code: def get_certificates(self):
          
          fps = []
          certs = []
          for x in self.get_certificates_v1() + self.get_certificates_v2() + self.get_certificates_v3():
              if x.sha256 not in fps:
                  fps.append(x.sha256)
                  certs.append(x)
          return certs
docs: Return a list of unique :class:`asn1crypto.x509.Certificate` which are found
          in v1, v2 and v3 signing
          Note that we simply extract all certificates regardless of the signer.
          Therefore this is just a list of all certificates found in all signers.