if self._ignore_certificates:
-    pool_manager_init_args["cert_reqs"] = "CERT_NONE"
-    urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
+    pool_manager_init_args["cert_reqs"] = "CERT_REQUIRED"
+    pool_manager_init_args["cert_file"] = "/path/to/custom/cert.pem"
+    pool_manager_init_args["assert_hostname"] = False

 def execute(self, command, params):
     """Send a command to the remote server.
 
     Any path substitutions required for the URL mapped to the command should be
     included in the command parameters.
 
     :Args:
      - command - A string specifying the command to execute.
      - params - A dictionary of named parameters to send with the command as
        its JSON payload.
+    :Raises:
+     - UnknownCommandError: If the command is not recognized.
+     - CommandExecutionError: If there's an error during command execution.
     """
-    command_info = self._commands.get(command) or self.extra_commands.get(command)
-    assert command_info is not None, f"Unrecognised command {command}"
-    path_string = command_info[1]
-    path = string.Template(path_string).substitute(params)
+    try:
+        command_info = self._commands.get(command) or self.extra_commands.get(command)
+        if command_info is None:
+            raise UnknownCommandError(f"Unrecognised command {command}")
+        path_string = command_info[1]
+        path = string.Template(path_string).substitute(params)
+        # ... rest of the method implementation
+    except Exception as e:
+        logging.error(f"Error executing command {command}: {str(e)}")
+        raise CommandExecutionError(f"Error executing {command}: {str(e)}") from e

-extra_headers = None
+@classmethod
+def add_header(cls, key, value):
+    if cls.extra_headers is None:
+        cls.extra_headers = {}
+    cls.extra_headers[key] = value
 
+@classmethod
+def remove_header(cls, key):
+    if cls.extra_headers and key in cls.extra_headers:
+        del cls.extra_headers[key]
+

 @classmethod
 def add_command(cls, name, method, url):
     """Register a new command."""
-    cls.extra_commands[name] = (method, url)
+    cls.extra_commands[name] = {"method": method, "url": url}
 
+@classmethod
+def remove_command(cls, name):
+    """Remove a registered command."""
+    if name in cls.extra_commands:
+        del cls.extra_commands[name]
+