def insert(self, database, key, value, callback=None):
token = self._get_token()<EOL>self._enqueue(self._PendingItem(token, BlobCommand(token=token, database=database,<EOL>content=InsertCommand(key=key.bytes, value=value)),<EOL>callback))<EOL>
Insert an item into the given database.

:param database: The database into which to insert the value.
:type database: .BlobDatabaseID
:param key: The key to insert.
:type key: uuid.UUID
:param value: The value to insert.
:type value: bytes
:param callback: A callback to be called on success or failure.