Update quotes in use-cases example

Author: rmk135

examples/miniapps/use-cases/example/__main__.py

@@ -6,18 +6,18 @@
 
 
 def main(environment: str, email: str) -> None:
-    if environment == 'prod':
+    if environment == "prod":
         adapters = Adapters()
-    elif environment == 'test':
+    elif environment == "test":
         adapters = TestAdapters()
     else:
-        raise RuntimeError('Unknown environment')
+        raise RuntimeError("Unknown environment")
 
     use_cases = UseCases(adapters=adapters)
 
     use_case = use_cases.signup()
     use_case.execute(email)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main(*sys.argv[1:])

examples/miniapps/use-cases/example/adapters.py

@@ -13,10 +13,10 @@ def send(self, to: str, body: str) -> None:
 class SmtpEmailSender:
 
     def send(self, to: str, body: str) -> None:
-        print(f'Sending an email to {to} over SMTP, body="{body}"')
+        print(f"Sending an email to {to} over SMTP, body=\"{body}\"")
 
 
 class EchoEmailSender:
 
     def send(self, to: str, body: str) -> None:
-        print(f'Fake sending an email to {to}, body="{body}"')
+        print(f"Fake sending an email to {to}, body=\"{body}\"")

examples/miniapps/use-cases/example/usecases.py

@@ -18,5 +18,5 @@ def __init__(self, email_sender: EmailSender) -> None:
         self.email_sender = email_sender
 
     def execute(self, email: str) -> None:
-        print(f'Sign up user {email}')
-        self.email_sender.send(email, f'Welcome, {email}')
+        print(f"Sign up user {email}")
+        self.email_sender.send(email, f"Welcome, {email}")