tests: make whitespace between functions and classes consistent

Mostly, this means two blank lines between classes and functions and one
line between methods. Since these checks are currently in preview, they
are done in a separate ruff invocation to avoid turning ALL the preview
checks on at the same time.

tests/negtelnetserver.py

@@ -38,6 +38,7 @@ if sys.version_info.major >= 3:
 else:
     import SocketServer as socketserver
 
+
 log = logging.getLogger(__name__)
 HOST = "localhost"
 IDENT = "NTEL"
@@ -46,6 +47,7 @@ IDENT = "NTEL"
 VERIFIED_REQ = "verifiedserver"
 VERIFIED_RSP = "WE ROOLZ: {pid}"
 
+
 def telnetserver(options):
     """Start up a TCP server with a telnet handler and serve DICT requests forever."""
     if options.pidfile:
@@ -66,6 +68,7 @@ def telnetserver(options):
     # leaving `with` calls server.close() automatically
     return ScriptRC.SUCCESS
 
+
 class NegotiatingTelnetHandler(socketserver.BaseRequestHandler):
     """Handler class for Telnet connections."""
 
@@ -109,6 +112,7 @@ class NegotiatingTelnetHandler(socketserver.BaseRequestHandler):
         except IOError:
             log.exception("IOError hit during request")
 
+
 class Negotiator:
     NO_NEG = 0
     START_NEG = 1
@@ -237,6 +241,7 @@ class Negotiator:
         log.debug("Sending WONT %s", option_str)
         self.send_iac([NegTokens.WONT, NegOptions.to_val(option_str)])
 
+
 class NegBase:
     @classmethod
     def to_val(cls, name):
@@ -250,6 +255,7 @@ class NegBase:
 
         return "<unknown>"
 
+
 class NegTokens(NegBase):
     # The start of a negotiation sequence
     IAC = 255
@@ -267,6 +273,7 @@ class NegTokens(NegBase):
     # The end of sub-negotiation options.
     SE = 240
 
+
 class NegOptions(NegBase):
     # Binary Transmission
     BINARY = 0
@@ -279,6 +286,7 @@ class NegOptions(NegBase):
     # Charset option
     CHARSET = 42
 
+
 def get_options():
     parser = argparse.ArgumentParser()
 
@@ -297,6 +305,7 @@ def get_options():
 
     return parser.parse_args()
 
+
 def setup_logging(options):
     """Set up logging from the command line options."""
     root_logger = logging.getLogger()
@@ -329,6 +338,7 @@ def setup_logging(options):
         stdout_handler.setLevel(logging.DEBUG)
         root_logger.addHandler(stdout_handler)
 
+
 class ScriptRC:
     """Enum for script return codes."""
 
@@ -336,6 +346,7 @@ class ScriptRC:
     FAILURE = 1
     EXCEPTION = 2
 
+
 if __name__ == '__main__':
     # Get the options from the user.
     options = get_options()