"""
User Message module for MCP.

This module is intended to define the UserMessage class, which would represent
messages sent by users in the Model Control Protocol (MCP) system.

The UserMessage class would be the counterpart to AssistantMessage, representing
the user side of conversations with a fixed role of "user" and potentially
supporting various content types similar to AssistantMessage.

Note: This module is currently a placeholder and does not contain an implementation
of the UserMessage class yet.
"""
