diff --git a/src/agents/visualizations.py b/src/agents/visualizations.py
index 934647f..42019d4 100644
--- a/src/agents/visualizations.py
+++ b/src/agents/visualizations.py
@@ -13,7 +13,8 @@ def get_main_graph(agent: Agent) -> str:
     Returns:
         str: The DOT format string representing the graph.
     """
-    parts = ["""
+    parts = [
+        """
     digraph G {
         graph [splines=true];
         node [fontname="Arial"];
@@ -21,7 +22,8 @@ def get_main_graph(agent: Agent) -> str:
         
         "__start__" [shape=ellipse, style=filled, fillcolor=lightblue];
         "__end__" [shape=ellipse, style=filled, fillcolor=lightblue];
-    """]
+    """
+    ]
     parts.append(get_all_nodes(agent))
     parts.append(get_all_edges(agent))
     parts.append("}")
@@ -39,23 +41,23 @@ def get_all_nodes(agent: Agent, parent: Agent = None) -> str:
         str: The DOT format string representing the nodes.
     """
     parts = []
-    
+
     # Ensure parent agent node is colored
     if not parent:
         parts.append(f"""
         "{agent.name}" [label="{agent.name}", shape=box, style=filled, fillcolor=lightyellow, width=1.5, height=0.8];""")
-    
+
     # Smaller tools (ellipse, green)
     for tool in agent.tools:
         parts.append(f"""
         "{tool.name}" [label="{tool.name}", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];""")
-    
+
     # Bigger handoffs (rounded box, yellow)
     for handoff in agent.handoffs:
         parts.append(f"""
         "{handoff.name}" [label="{handoff.name}", shape=box, style=filled, style=rounded, fillcolor=lightyellow, width=1.5, height=0.8];""")
         parts.append(get_all_nodes(handoff))
-    
+
     return "".join(parts)
 
 
@@ -71,25 +73,25 @@ def get_all_edges(agent: Agent, parent: Agent = None) -> str:
         str: The DOT format string representing the edges.
     """
     parts = []
-    
+
     if not parent:
         parts.append(f"""
         "__start__" -> "{agent.name}";""")
-    
+
     for tool in agent.tools:
         parts.append(f"""
         "{agent.name}" -> "{tool.name}" [style=dotted, penwidth=1.5];
         "{tool.name}" -> "{agent.name}" [style=dotted, penwidth=1.5];""")
-    
+
     if not agent.handoffs:
         parts.append(f"""
         "{agent.name}" -> "__end__";""")
-    
+
     for handoff in agent.handoffs:
         parts.append(f"""
         "{agent.name}" -> "{handoff.name}";""")
         parts.append(get_all_edges(handoff, agent))
-    
+
     return "".join(parts)
 
 
@@ -106,8 +108,8 @@ def draw_graph(agent: Agent, filename: str = None) -> graphviz.Source:
     """
     dot_code = get_main_graph(agent)
     graph = graphviz.Source(dot_code)
-    
+
     if filename:
-        graph.render(filename, format='png')
-    
-    return graph
\ No newline at end of file
+        graph.render(filename, format="png")
+
+    return graph
diff --git a/tests/test_visualizations.py b/tests/test_visualizations.py
index 0062f85..d813978 100644
--- a/tests/test_visualizations.py
+++ b/tests/test_visualizations.py
@@ -1,8 +1,11 @@
-import pytest
 from unittest.mock import Mock
-from src.agents.visualizations import get_main_graph, get_all_nodes, get_all_edges, draw_graph
-from src.agents.agent import Agent
+
 import graphviz
+import pytest
+
+from src.agents.agent import Agent
+from src.agents.visualizations import draw_graph, get_all_edges, get_all_nodes, get_main_graph
+
 
 @pytest.fixture
 def mock_agent():
@@ -10,7 +13,7 @@ def mock_agent():
     tool1.name = "Tool1"
     tool2 = Mock()
     tool2.name = "Tool2"
-    
+
     handoff1 = Mock()
     handoff1.name = "Handoff1"
     handoff1.tools = []
@@ -20,28 +23,55 @@ def mock_agent():
     agent.name = "Agent1"
     agent.tools = [tool1, tool2]
     agent.handoffs = [handoff1]
-    
+
     return agent
 
+
 def test_get_main_graph(mock_agent):
     result = get_main_graph(mock_agent)
     assert "digraph G" in result
-    assert 'graph [splines=true];' in result
+    assert "graph [splines=true];" in result
     assert 'node [fontname="Arial"];' in result
-    assert 'edge [penwidth=1.5];' in result
+    assert "edge [penwidth=1.5];" in result
     assert '"__start__" [shape=ellipse, style=filled, fillcolor=lightblue];' in result
     assert '"__end__" [shape=ellipse, style=filled, fillcolor=lightblue];' in result
-    assert '"Agent1" [label="Agent1", shape=box, style=filled, fillcolor=lightyellow, width=1.5, height=0.8];' in result
-    assert '"Tool1" [label="Tool1", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];' in result
-    assert '"Tool2" [label="Tool2", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];' in result
-    assert '"Handoff1" [label="Handoff1", shape=box, style=filled, style=rounded, fillcolor=lightyellow, width=1.5, height=0.8];' in result
+    assert (
+        '"Agent1" [label="Agent1", shape=box, style=filled, fillcolor=lightyellow, width=1.5, height=0.8];'
+        in result
+    )
+    assert (
+        '"Tool1" [label="Tool1", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];'
+        in result
+    )
+    assert (
+        '"Tool2" [label="Tool2", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];'
+        in result
+    )
+    assert (
+        '"Handoff1" [label="Handoff1", shape=box, style=filled, style=rounded, fillcolor=lightyellow, width=1.5, height=0.8];'
+        in result
+    )
+
 
 def test_get_all_nodes(mock_agent):
     result = get_all_nodes(mock_agent)
-    assert '"Agent1" [label="Agent1", shape=box, style=filled, fillcolor=lightyellow, width=1.5, height=0.8];' in result
-    assert '"Tool1" [label="Tool1", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];' in result
-    assert '"Tool2" [label="Tool2", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];' in result
-    assert '"Handoff1" [label="Handoff1", shape=box, style=filled, style=rounded, fillcolor=lightyellow, width=1.5, height=0.8];' in result
+    assert (
+        '"Agent1" [label="Agent1", shape=box, style=filled, fillcolor=lightyellow, width=1.5, height=0.8];'
+        in result
+    )
+    assert (
+        '"Tool1" [label="Tool1", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];'
+        in result
+    )
+    assert (
+        '"Tool2" [label="Tool2", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];'
+        in result
+    )
+    assert (
+        '"Handoff1" [label="Handoff1", shape=box, style=filled, style=rounded, fillcolor=lightyellow, width=1.5, height=0.8];'
+        in result
+    )
+
 
 def test_get_all_edges(mock_agent):
     result = get_all_edges(mock_agent)
@@ -53,16 +83,29 @@ def test_get_all_edges(mock_agent):
     assert '"Agent1" -> "Handoff1";' in result
     assert '"Handoff1" -> "__end__";' in result
 
+
 def test_draw_graph(mock_agent):
     graph = draw_graph(mock_agent)
     assert isinstance(graph, graphviz.Source)
     assert "digraph G" in graph.source
-    assert 'graph [splines=true];' in graph.source
+    assert "graph [splines=true];" in graph.source
     assert 'node [fontname="Arial"];' in graph.source
-    assert 'edge [penwidth=1.5];' in graph.source
+    assert "edge [penwidth=1.5];" in graph.source
     assert '"__start__" [shape=ellipse, style=filled, fillcolor=lightblue];' in graph.source
     assert '"__end__" [shape=ellipse, style=filled, fillcolor=lightblue];' in graph.source
-    assert '"Agent1" [label="Agent1", shape=box, style=filled, fillcolor=lightyellow, width=1.5, height=0.8];' in graph.source
-    assert '"Tool1" [label="Tool1", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];' in graph.source
-    assert '"Tool2" [label="Tool2", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];' in graph.source
-    assert '"Handoff1" [label="Handoff1", shape=box, style=filled, style=rounded, fillcolor=lightyellow, width=1.5, height=0.8];' in graph.source
+    assert (
+        '"Agent1" [label="Agent1", shape=box, style=filled, fillcolor=lightyellow, width=1.5, height=0.8];'
+        in graph.source
+    )
+    assert (
+        '"Tool1" [label="Tool1", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];'
+        in graph.source
+    )
+    assert (
+        '"Tool2" [label="Tool2", shape=ellipse, style=filled, fillcolor=lightgreen, width=0.5, height=0.3];'
+        in graph.source
+    )
+    assert (
+        '"Handoff1" [label="Handoff1", shape=box, style=filled, style=rounded, fillcolor=lightyellow, width=1.5, height=0.8];'
+        in graph.source
+    )