diff --git a/tests/graphs/abstract_graph_test.py b/tests/graphs/abstract_graph_test.py
index c17ef09a..280f1f77 100644
--- a/tests/graphs/abstract_graph_test.py
+++ b/tests/graphs/abstract_graph_test.py
@@ -1,18 +1,16 @@
-"""
-Tests for the AbstractGraph.
-"""
-
-from unittest.mock import patch
-
 import pytest
+
 from langchain_aws import ChatBedrock
 from langchain_ollama import ChatOllama
 from langchain_openai import AzureChatOpenAI, ChatOpenAI
-
 from scrapegraphai.graphs import AbstractGraph, BaseGraph
 from scrapegraphai.models import DeepSeek, OneApi
 from scrapegraphai.nodes import FetchNode, ParseNode
+from unittest.mock import Mock, patch
 
+"""
+Tests for the AbstractGraph.
+"""
 
 class TestGraph(AbstractGraph):
     def __init__(self, prompt: str, config: dict):
@@ -50,7 +48,6 @@ class TestGraph(AbstractGraph):
 
         return self.final_state.get("answer", "No answer found.")
 
-
 class TestAbstractGraph:
     @pytest.mark.parametrize(
         "llm_config, expected_model",
@@ -161,3 +158,45 @@ class TestAbstractGraph:
             result = await graph.run_safe_async()
             assert result == "Async result"
             mock_run.assert_called_once()
+
+    def test_create_llm_with_custom_model_instance(self):
+        """
+        Test that the _create_llm method correctly uses a custom model instance
+        when provided in the configuration.
+        """
+        mock_model = Mock()
+        mock_model.model_name = "custom-model"
+
+        config = {
+            "llm": {
+                "model_instance": mock_model,
+                "model_tokens": 1000,
+                "model": "custom/model"
+            }
+        }
+
+        graph = TestGraph("Test prompt", config)
+
+        assert graph.llm_model == mock_model
+        assert graph.model_token == 1000
+
+    def test_set_common_params(self):
+        """
+        Test that the set_common_params method correctly updates the configuration
+        of all nodes in the graph.
+        """
+        # Create a mock graph with mock nodes
+        mock_graph = Mock()
+        mock_node1 = Mock()
+        mock_node2 = Mock()
+        mock_graph.nodes = [mock_node1, mock_node2]
+
+        # Create a TestGraph instance with the mock graph
+        with patch('scrapegraphai.graphs.abstract_graph.AbstractGraph._create_graph', return_value=mock_graph):
+            graph = TestGraph("Test prompt", {"llm": {"model": "openai/gpt-3.5-turbo", "openai_api_key": "sk-test"}})
+
+        # Call set_common_params with test parameters
+        test_params = {"param1": "value1", "param2": "value2"}
+        graph.set_common_params(test_params)
+
+        # Assert that update_config was called on each node with the correct parameters
\ No newline at end of file