diff --git a/examples/example.py b/examples/example.py
index 07c3b15..332b39f 100644
--- a/examples/example.py
+++ b/examples/example.py
@@ -19,9 +19,8 @@
 # header.add_substitution('key', 'value')
 header.set_substitutions({'key': ['value1', 'value2']})
 
-# [Unique Arguments]
-# (http://sendgrid.com/docs/API_Reference/SMTP_API/unique_arguments.html)
-# header.add_unique_arg('key', 'value')
+# [Unique Arguments](http://sendgrid.com/docs/API_Reference/SMTP_API/unique_arguments.html)
+#header.add_unique_arg('key', 'value')
 header.set_unique_args({'key': 'value'})
 
 # [Categories](http://sendgrid.com/docs/API_Reference/SMTP_API/categories.html)
@@ -44,10 +43,9 @@
 # (https://sendgrid.com/docs/API_Reference/Web_API_v3/IP_Management/ip_pools.html)
 header.set_ip_pool("testPool")
 
-# [Scheduling Parameters]
-# (https://sendgrid.com/docs/API_Reference/SMTP_API/scheduling_parameters.html)
-# header.add_send_each_at(unix_timestamp) #  must be a unix timestamp
-# header.set_send_each_at([]) #  must be a unix timestamp
+# [Scheduling Parameters](https://sendgrid.com/docs/API_Reference/SMTP_API/scheduling_parameters.html)
+# header.add_send_each_at(unix_timestamp) # must be a unix timestamp
+# header.set_send_each_at([]) # must be a unix timestamp
 header.set_send_at(int(time.time()))  # must be a unix timestamp
 
 print(header.json_string())
diff --git a/smtpapi/__init__.py b/smtpapi/__init__.py
index 1ed55a7..44ff7da 100644
--- a/smtpapi/__init__.py
+++ b/smtpapi/__init__.py
@@ -1,104 +1,101 @@
-import json
-import decimal
-
-
-class _CustomJSONEncoder(json.JSONEncoder):
-
-    def default(self, o):
-        if isinstance(o, decimal.Decimal):
-            return float(o)
-        # Provide a fallback to the default encoder if we haven't implemented
-        # special support for the object's class
-        return super(_CustomJSONEncoder, self).default(o)
-
-
-class SMTPAPIHeader(object):
-
-    def __init__(self):
-        self.data = {}
-
-    def add_to(self, to):
-        if 'to' not in self.data:
-            self.data['to'] = []
-        if type(to) is list:
-            self.data['to'] += to
-        else:
-            self.data['to'].append(to)
-
-    def set_tos(self, tos):
-        self.data['to'] = tos
-
-    def add_substitution(self, key, value):
-        if 'sub' not in self.data:
-            self.data['sub'] = {}
-        if key not in self.data['sub']:
-            self.data['sub'][key] = []
-        self.data['sub'][key].append(value)
-
-    def set_substitutions(self, subs):
-        self.data['sub'] = subs
-
-    def _add_key_value(self, index, key, value):
-        if index not in self.data:
-            self.data[index] = {}
-        self.data[index][key] = value
-
-    def _add_key(self, index, key):
-        if index not in self.data:
-            self.data[index] = []
-        self.data[index].append(key)
-
-    def add_unique_arg(self, key, value):
-        self._add_key_value('unique_args', key, value)
-
-    def set_unique_args(self, value):
-        self.data['unique_args'] = value
-
-    def add_category(self, category):
-        self._add_key('category', category)
-
-    def set_categories(self, category):
-        self.data['category'] = category
-
-    def add_section(self, key, section):
-        self._add_key_value('section', key, section)
-
-    def set_sections(self, value):
-        self.data['section'] = value
-
-    def add_send_each_at(self, time):
-        self._add_key('send_each_at', time)
-
-    def set_send_each_at(self, time):
-        self.data['send_each_at'] = time
-
-    def set_send_at(self, time):
-        self.data['send_at'] = time
-
-    def add_filter(self, app, setting, val):
-        if 'filters' not in self.data:
-            self.data['filters'] = {}
-        if app not in self.data['filters']:
-            self.data['filters'][app] = {}
-        if 'settings' not in self.data['filters'][app]:
-            self.data['filters'][app]['settings'] = {}
-        self.data['filters'][app]['settings'][setting] = val
-
-    def set_asm_group_id(self, value):
-        if not bool(value):
-            self.data['asm_group_id'] = {}
-        else:
-            self.data['asm_group_id'] = value
-
-    def set_ip_pool(self, value):
-        if bool(value):
-            self.data['ip_pool'] = value
-        else:
-            self.data['ip_pool'] = {}
-
-    def json_string(self):
-        result = {}
-        for key in self.data.keys():
-            if self.data[key] != [] and self.data[key] != {}:
-                result[key] = self.data[key]
-        return json.dumps(result, cls=_CustomJSONEncoder)
+import json
+import decimal
+
+
+class _CustomJSONEncoder(json.JSONEncoder):
+
+    def default(self, o):
+        if isinstance(o, decimal.Decimal):
+            return float(o)
+        # Provide a fallback to the default encoder if we haven't implemented special support for the object's class
+        return super(_CustomJSONEncoder, self).default(o)
+
+
+class SMTPAPIHeader(object):
+
+    def __init__(self):
+        self.data = {}
+
+    def add_to(self, to):
+        if 'to' not in self.data:
+            self.data['to'] = []
+        if type(to) is list:
+            self.data['to'] += to
+        else:
+            self.data['to'].append(to)
+
+    def set_tos(self, tos):
+        self.data['to'] = tos
+
+    def add_substitution(self, key, value):
+        if 'sub' not in self.data:
+            self.data['sub'] = {}
+        if key not in self.data['sub']:
+            self.data['sub'][key] = []
+        self.data['sub'][key].append(value)
+
+    def set_substitutions(self, subs):
+        self.data['sub'] = subs
+
+    def add_unique_arg(self, key, value):
+        if 'unique_args' not in self.data:
+            self.data['unique_args'] = {}
+        self.data['unique_args'][key] = value
+
+    def set_unique_args(self, value):
+        self.data['unique_args'] = value
+
+    def add_category(self, category):
+        if 'category' not in self.data:
+            self.data['category'] = []
+        self.data['category'].append(category)
+
+    def set_categories(self, category):
+        self.data['category'] = category
+
+    def add_section(self, key, section):
+        if 'section' not in self.data:
+            self.data['section'] = {}
+        self.data['section'][key] = section
+
+    def set_sections(self, value):
+        self.data['section'] = value
+
+    def add_send_each_at(self, time):
+        if 'send_each_at' not in self.data:
+            self.data['send_each_at'] = []
+        self.data['send_each_at'].append(time)
+
+    def set_send_each_at(self, time):
+        self.data['send_each_at'] = time
+
+    def set_send_at(self, time):
+        self.data['send_at'] = time
+
+    def add_filter(self, app, setting, val):
+        if 'filters' not in self.data:
+            self.data['filters'] = {}
+        if app not in self.data['filters']:
+            self.data['filters'][app] = {}
+        if 'settings' not in self.data['filters'][app]:
+            self.data['filters'][app]['settings'] = {}
+        self.data['filters'][app]['settings'][setting] = val
+
+    def set_asm_group_id(self, value):
+        if not bool(value):
+            self.data['asm_group_id'] = {}
+        else:
+            self.data['asm_group_id'] = value
+
+    def set_ip_pool(self, value):
+        if bool(value):
+            self.data['ip_pool'] = value
+        else:
+            self.data['ip_pool'] = {}
+
+    def json_string(self):
+        result = {}
+        for key in self.data.keys():
+            if self.data[key] != [] and self.data[key] != {}:
+                result[key] = self.data[key]
+        return json.dumps(result, cls=_CustomJSONEncoder)
diff --git a/test/__init__.py b/test/__init__.py
index 00ff8b8..5c450e9 100644
--- a/test/__init__.py
+++ b/test/__init__.py
@@ -1,5 +1,5 @@
-import decimal
 import json
+import decimal
 import os
 import datetime