diff --git a/httprunner/api.py b/httprunner/api.py
index 6f8770eb..2d17af46 100644
--- a/httprunner/api.py
+++ b/httprunner/api.py
@@ -16,14 +16,11 @@ class HttpRunner(object):
             kwargs (dict): key-value arguments used to initialize TextTestRunner.
             Commonly used arguments:
 
-            resultclass (class): HtmlTestResult or TextTestResult
             failfast (bool): False/True, stop the test run on the first error or failure.
-            http_client_session (instance): requests.Session(), or locust.client.Session() instance.
 
         """
         self.exception_stage = "initialize HttpRunner()"
-        self.http_client_session = kwargs.pop("http_client_session", None)
-        kwargs.setdefault("resultclass", report.HtmlTestResult)
+        kwargs["resultclass"] = report.HtmlTestResult
         self.unittest_runner = unittest.TextTestRunner(**kwargs)
         self.test_loader = unittest.TestLoader()
         self.summary = None
@@ -63,7 +60,7 @@ class HttpRunner(object):
 
         for testcase in tests_mapping["testcases"]:
             config = testcase.get("config", {})
-            test_runner = runner.Runner(config, functions, self.http_client_session)
+            test_runner = runner.Runner(config, functions)
             TestSequense = type('TestSequense', (unittest.TestCase,), {})
 
             tests = testcase.get("tests", [])
@@ -125,7 +122,6 @@ class HttpRunner(object):
 
             self.summary["success"] &= testcase_summary["success"]
             testcase_summary["name"] = testcase.config.get("name")
-            testcase_summary["base_url"] = testcase.config.get("request", {}).get("base_url", "")
 
             in_out = utils.get_testcase_io(testcase)
             utils.print_io(in_out)
diff --git a/httprunner/parser.py b/httprunner/parser.py
index c3756472..7853778f 100644
--- a/httprunner/parser.py
+++ b/httprunner/parser.py
@@ -870,13 +870,6 @@ def parse_tests(tests_mapping):
     """
     project_mapping = tests_mapping.get("project_mapping", {})
 
-    env_mapping = project_mapping.get("env", {})
-    # set OS environment variables
-    utils.set_os_environ(env_mapping)
-
     for testcase in tests_mapping["testcases"]:
         testcase.setdefault("config", {})
         _parse_testcase(testcase, project_mapping)
-
-    # unset OS environment variables
-    utils.unset_os_environ(env_mapping)
diff --git a/httprunner/report.py b/httprunner/report.py
index 0da55305..af68e429 100644
--- a/httprunner/report.py
+++ b/httprunner/report.py
@@ -28,6 +28,10 @@ def get_platform():
 
 def get_summary(result):
     """ get summary from test result
+
+    Args:
+        result (instance): HtmlTestResult() instance
+
     """
     summary = {
         "success": result.wasSuccessful(),
@@ -47,14 +51,11 @@ def get_summary(result):
         - summary["stat"]["expectedFailures"] \
         - summary["stat"]["unexpectedSuccesses"]
 
-    if getattr(result, "records", None):
-        summary["time"] = {
-            'start_at': result.start_at,
-            'duration': result.duration
-        }
-        summary["records"] = result.records
-    else:
-        summary["records"] = []
+    summary["time"] = {
+        'start_at': result.start_at,
+        'duration': result.duration
+    }
+    summary["records"] = result.records
 
     return summary
 
@@ -173,9 +174,8 @@ def stringify_data(meta_data, request_or_response):
 
 
 class HtmlTestResult(unittest.TextTestResult):
-    """A html result class that can generate formatted html results.
-
-    Used by TextTestRunner.
+    """ A html result class that can generate formatted html results.
+        Used by TextTestRunner.
     """
     def __init__(self, stream, descriptions, verbosity):
         super(HtmlTestResult, self).__init__(stream, descriptions, verbosity)