Fix import statements and improve error handling in examples

examples/doc-examples/example_encryption_insecure.py

@@ -8,7 +8,7 @@ from libp2p import (
 from libp2p.crypto.secp256k1 import (
     create_new_key_pair,
 )
-from libp2p.security.insecure.transport import PLAINTEXT_PROTOCOL_ID, Transport
+from libp2p.security.insecure.transport import PLAINTEXT_PROTOCOL_ID, InsecureTransport
 from libp2p.utils.address_validation import (
     get_available_interfaces,
     get_optimal_binding_address,
@@ -21,7 +21,7 @@ async def main():
     key_pair = create_new_key_pair(secret)
 
     # Create an insecure transport (not recommended for production)
-    insecure_transport = Transport(
+    insecure_transport = InsecureTransport(
         # local_key_pair: The key pair used for libp2p identity
         local_key_pair=key_pair,
         # secure_bytes_provider: Optional function to generate secure random bytes

examples/doc-examples/example_peer_discovery.py

@@ -1,5 +1,6 @@
 import secrets
 
+from multiaddr import Multiaddr
 import trio
 
 from libp2p import (
@@ -66,7 +67,7 @@ async def main():
 
         for addr in bootstrap_list:
             try:
-                peer_info = info_from_p2p_addr(multiaddr.Multiaddr(addr))
+                peer_info = info_from_p2p_addr(Multiaddr(addr))
                 await host.connect(peer_info)
                 print(f"Connected to {peer_info.peer_id.to_string()}")
             except Exception as e:

examples/doc-examples/example_quic_transport.py

@@ -30,6 +30,7 @@ async def main():
     for addr in listen_addrs:
         addr_str = str(addr).replace("/tcp/", "/udp/") + "/quic-v1"
         from multiaddr import Multiaddr
+
         quic_addrs.append(Multiaddr(addr_str))
 
     optimal_addr = get_optimal_binding_address(port, protocol="udp")