How to use the pymongocrypt.errors.MongoCryptError function in pymongocrypt

def __init__(self, options):
        """Abstracts libmongocrypt's mongocrypt_t type.

        :Parameters:
          - `options`: A :class:`MongoCryptOptions`.
        """
        self.__opts = options
        self.__crypt = None

        if not isinstance(options, MongoCryptOptions):
            raise TypeError("options must be a MongoCryptOptions")

        self.__crypt = lib.mongocrypt_new()
        if self.__crypt == ffi.NULL:
            raise MongoCryptError("unable to create new mongocrypt object")

        try:
            self.__init()
        except Exception:
            # Destroy the mongocrypt object on error.
            self.close()
            raise

def __raise_from_status(self):
        status = lib.mongocrypt_status_new()
        try:
            lib.mongocrypt_kms_ctx_status(self.__ctx, status)
            exc = MongoCryptError.from_status(status)
        finally:
            lib.mongocrypt_status_destroy(status)
        raise exc

def __raise_from_status(self):
        status = lib.mongocrypt_status_new()
        try:
            lib.mongocrypt_status(self.__crypt, status)
            exc = MongoCryptError.from_status(status)
        finally:
            lib.mongocrypt_status_destroy(status)
        raise exc

mongocryptd_cmd = ctx.mongo_operation()
            result = callback.mark_command(ctx.database, mongocryptd_cmd)
            ctx.add_mongo_operation_result(result)
            ctx.complete_mongo_operation()
        elif state == lib.MONGOCRYPT_CTX_NEED_MONGO_KEYS:
            key_filter = ctx.mongo_operation()
            for key in callback.fetch_keys(key_filter):
                ctx.add_mongo_operation_result(key)
            ctx.complete_mongo_operation()
        elif state == lib.MONGOCRYPT_CTX_NEED_KMS:
            for kms_ctx in ctx.kms_contexts():
                with kms_ctx:
                    callback.kms_request(kms_ctx)
            ctx.complete_kms()
        else:
            raise MongoCryptError('unknown state: %r' % (state,))