docs: def from_inline(cls: Type[CertificationType], version: int, currency: str, blockhash: Optional[str],
                      inline: str) -> CertificationType:
          """
          Return Certification instance from inline document
  
          Only self.pubkey_to is populated.
          You must populate self.identity with an Identity instance to use raw/sign/signed_raw methods
  
          :param version: Version of document
          :param currency: Name of the currency
          :param blockhash: Hash of the block
          :param inline: Inline document
          :return:
          """
          cert_data = Certification.re_inline.match(inline)
          if cert_data is None:
              raise MalformedDocumentError("Certification ({0})".format(inline))
          pubkey_from = cert_data.group(1)
          pubkey_to = cert_data.group(2)
          blockid = int(cert_data.group(3))
          if blockid == 0 or blockhash is None:
              timestamp = BlockUID.empty()
          else:
              timestamp = BlockUID(blockid, blockhash)
  
          signature = cert_data.group(4)
          return cls(version, currency, pubkey_from, pubkey_to, timestamp, signature)