Try to fix "This event loop is already running" errors

tracer.py

@@ -12,6 +12,7 @@ from functools import cached_property
 from pathlib import Path
 from typing import Any, Iterator, Optional, TypedDict
 
+import nest_asyncio
 import pyshark
 from prompt_toolkit.formatted_text import HTML
 from prompt_toolkit.shortcuts import ProgressBar
@@ -24,6 +25,9 @@ if typing.TYPE_CHECKING:
     from pyshark.packet.packet import Packet
 
 
+# https://github.com/KimiNewt/pyshark/issues/434#issuecomment-691706873
+nest_asyncio.apply()
+
 QuicStreamPacket = Any
 
 
@@ -293,6 +297,8 @@ class Trace:
 
             packets.append(packet)
 
+        # https://github.com/KimiNewt/pyshark/issues/366#issuecomment-524746268
+        self._cap.close()
         self._packets = packets
 
     @staticmethod