Chat Message.
Merge multiple message contents.
Merge dictionaries.
Merge many dicts, handling specific scenarios where a key exists in both
dictionaries but has a value of None in 'left'. In such cases, the method uses
the value from 'right' for that key in the merged dictionary.
Base abstract message class.
Messages are the inputs and outputs of a chat model.
Examples include HumanMessage,
AIMessage, and
SystemMessage.
Message chunk, which can be concatenated with other Message chunks.
Message that can be assigned an arbitrary speaker (i.e. role).
Chat Message chunk.