Made a configurable constant (#1819)

* Made a configurable constant

* Fix typo

Co-authored-by: Joshua Kim <joshkyh@users.noreply.github.com>

---------

Co-authored-by: Joshua Kim <joshkyh@users.noreply.github.com>

autogen/agentchat/groupchat.py

@@ -78,6 +78,11 @@ def custom_speaker_selection_func(
     _VALID_SPEAKER_SELECTION_METHODS = ["auto", "manual", "random", "round_robin"]
     _VALID_SPEAKER_TRANSITIONS_TYPE = ["allowed", "disallowed", None]
 
+    # Define a class attribute for the default introduction message
+    DEFAULT_INTRO_MSG = (
+        "Hello everyone. We have assembled a great team today to answer questions and solve tasks. In attendance are:"
+    )
+
     allowed_speaker_transitions_dict: Dict = field(init=False)
 
     def __post_init__(self):
@@ -244,10 +249,11 @@ def introductions_msg(self, agents: Optional[List[Agent]] = None) -> str:
         if agents is None:
             agents = self.agents
 
-        return f"""Hello everyone. We have assembled a great team today to answer questions and solve tasks. In attendance are:
+        # Use the class attribute instead of a hardcoded string
+        intro_msg = self.DEFAULT_INTRO_MSG
+        participant_roles = self._participant_roles(agents)
 
-{self._participant_roles(agents)}
-"""
+        return f"{intro_msg}\n\n{participant_roles}"
 
     def manual_select_speaker(self, agents: Optional[List[Agent]] = None) -> Union[Agent, None]:
         """Manually select the next speaker."""