feat: create chat message

src/AnthropicClient/Models/MessageRequest.cs

@@ -0,0 +1,22 @@
+namespace AnthropicClient.Models;
+
+/// <summary>
+/// Represents a message request.
+/// </summary>
+public abstract class MessageRequest
+{
+  /// <summary>
+  /// Gets a value indicating whether the message should be streamed.
+  /// </summary>
+  public bool Stream { get; init; }
+
+  /// <summary>
+  /// Initializes a new instance of the <see cref="MessageRequest"/> class.
+  /// </summary>
+  /// <param name="stream">A value indicating whether the message should be streamed.</param>
+  /// <returns>A new instance of the <see cref="MessageRequest"/> class.</returns>
+  public MessageRequest(bool stream = false)
+  {
+    Stream = stream;
+  }
+}