docs: def validate_config(cls, config):
          """
          Validates that a config file path and a control socket file path
          and pid file path are all present in the HAProxy config.
          """
          if "config_file" not in config:
              raise ValueError("No config file path given")
          if "socket_file" not in config:
              raise ValueError("No control socket path given")
          if "pid_file" not in config:
              raise ValueError("No PID file path given")
          if "stats" in config and "port" not in config["stats"]:
              raise ValueError("Stats interface defined, but no port given")
          if "proxies" in config:
              cls.validate_proxies_config(config["proxies"])
  
          return config