diff --git a/k8sclient/client/api_client.py b/k8sclient/client/api_client.py
index 62bd226..4e01463 100644
--- a/k8sclient/client/api_client.py
+++ b/k8sclient/client/api_client.py
@@ -65,7 +65,8 @@ class ApiClient(object):
     :param header_value: a header value to pass when making calls to the API.
     """
     def __init__(self, host=Configuration().host,
-                 header_name=None, header_value=None, cookie=None):
+                 header_name=None, header_value=None, cookie=None,
+                 key_file=None, cert_file=None, ca_certs=None):
 
         """
         Constructor of the class.
@@ -77,6 +78,9 @@ class ApiClient(object):
         self.cookie = cookie
         # Set default User-Agent.
         self.user_agent = 'Python-Swagger'
+        self.RESTClient = RESTClient(key_file=key_file,
+                                     cert_file=cert_file,
+                                     ca_certs=ca_certs)
 
     @property
     def user_agent(self):
@@ -325,38 +329,38 @@ class ApiClient(object):
     def request(self, method, url, query_params=None, headers=None,
                 post_params=None, body=None):
         """
-        Makes the HTTP request using RESTClient.
+        Makes the HTTP request using instance of rest client.
         """
         if method == "GET":
-            return RESTClient.GET(url,
-                                  query_params=query_params,
-                                  headers=headers)
+            return self.RESTClient.GET(url,
+                                       query_params=query_params,
+                                       headers=headers)
         elif method == "HEAD":
-            return RESTClient.HEAD(url,
-                                   query_params=query_params,
-                                   headers=headers)
+            return self.RESTClient.HEAD(url,
+                                        query_params=query_params,
+                                        headers=headers)
         elif method == "POST":
-            return RESTClient.POST(url,
-                                   query_params=query_params,
-                                   headers=headers,
-                                   post_params=post_params,
-                                   body=body)
+            return self.RESTClient.POST(url,
+                                        query_params=query_params,
+                                        headers=headers,
+                                        post_params=post_params,
+                                        body=body)
         elif method == "PUT":
-            return RESTClient.PUT(url,
-                                  query_params=query_params,
-                                  headers=headers,
-                                  post_params=post_params,
-                                  body=body)
+            return self.RESTClient.PUT(url,
+                                       query_params=query_params,
+                                       headers=headers,
+                                       post_params=post_params,
+                                       body=body)
         elif method == "PATCH":
-            return RESTClient.PATCH(url,
-                                    query_params=query_params,
-                                    headers=headers,
-                                    post_params=post_params,
-                                    body=body)
+            return self.RESTClient.PATCH(url,
+                                         query_params=query_params,
+                                         headers=headers,
+                                         post_params=post_params,
+                                         body=body)
         elif method == "DELETE":
-            return RESTClient.DELETE(url,
-                                     query_params=query_params,
-                                     headers=headers)
+            return self.RESTClient.DELETE(url,
+                                          query_params=query_params,
+                                          headers=headers)
         else:
             raise ValueError(
                 "http method must be `GET`, `HEAD`,"
diff --git a/k8sclient/client/rest.py b/k8sclient/client/rest.py
index e5725a8..14bb913 100644
--- a/k8sclient/client/rest.py
+++ b/k8sclient/client/rest.py
@@ -232,56 +232,52 @@ class ApiException(Exception):
 
 class RESTClient(object):
     """
-    A class with all class methods to perform JSON requests.
+    A class with methods to perform JSON requests.
     """
 
-    IMPL = RESTClientObject()
+    def __init__(self, key_file=None, cert_file=None, ca_certs=None):
+        self.IMPL = RESTClientObject(key_file=key_file,
+                                     cert_file=cert_file,
+                                     ca_certs=ca_certs)
 
-    @classmethod
-    def request(cls, *n, **kw):
+    def request(self, *n, **kw):
         """
         Perform a REST request and parse the response.
         """
-        return cls.IMPL.request(*n, **kw)
+        return self.IMPL.request(*n, **kw)
 
-    @classmethod
-    def GET(cls, *n, **kw):
+    def GET(self, *n, **kw):
         """
         Perform a GET request using `RESTClient.request()`.
         """
-        return cls.IMPL.GET(*n, **kw)
+        return self.IMPL.GET(*n, **kw)
 
-    @classmethod
-    def HEAD(cls, *n, **kw):
+    def HEAD(self, *n, **kw):
         """
         Perform a HEAD request using `RESTClient.request()`.
         """
-        return cls.IMPL.GET(*n, **kw)
+        return self.IMPL.GET(*n, **kw)
 
-    @classmethod
-    def POST(cls, *n, **kw):
+    def POST(self, *n, **kw):
         """
         Perform a POST request using `RESTClient.request()`
         """
-        return cls.IMPL.POST(*n, **kw)
+        return self.IMPL.POST(*n, **kw)
 
-    @classmethod
-    def PUT(cls, *n, **kw):
+    def PUT(self, *n, **kw):
         """
         Perform a PUT request using `RESTClient.request()`
         """
-        return cls.IMPL.PUT(*n, **kw)
+        return self.IMPL.PUT(*n, **kw)
 
-    @classmethod
-    def PATCH(cls, *n, **kw):
+    def PATCH(self, *n, **kw):
         """
         Perform a PATCH request using `RESTClient.request()`
         """
-        return cls.IMPL.PATCH(*n, **kw)
+        return self.IMPL.PATCH(*n, **kw)
 
-    @classmethod
-    def DELETE(cls, *n, **kw):
+    def DELETE(self, *n, **kw):
         """
         Perform a DELETE request using `RESTClient.request()`
         """
-        return cls.IMPL.DELETE(*n, **kw)
+        return self.IMPL.DELETE(*n, **kw)