def merge_context(self, tag, metadata):
        """
        merge into contextManagerFrame new entity and metadata.

        Appends tag as new entity and adds keys in metadata to keys in
        self.metadata.

        Args:
            tag(str): entity to be added to self.entities
            metadata(object): metadata containes keys to be added to self.metadata
        """
        self.entities.append(tag)
        for k in metadata.keys():
            if k not in self.metadata:
                self.metadata[k] = k
merge into contextManagerFrame new entity and metadata.

        Appends tag as new entity and adds keys in metadata to keys in
        self.metadata.

        Args:
            tag(str): entity to be added to self.entities
            metadata(object): metadata containes keys to be added to self.metadata