chore(rich): make Rich_IcmpType hashable

src/firewall/core/rich.py

@@ -217,17 +217,20 @@ def __str__(self):
         return 'icmp-block name="%s"' % (self.name)
 
 
+@dataclass(frozen=True)
 class Rich_IcmpType(_Rich_Element):
-    def __init__(self, name):
-        self.name = name
+    """This object only holds data and is read-only after init. It is also
+    hashable and can be used as a dictionary key."""
 
-    def __str__(self):
-        return 'icmp-type name="%s"' % (self.name)
+    name: str
 
-    def check(self, family=None):
+    def __post_init__(self):
         if self.name is None or len(self.name) < 1:
             raise FirewallError(errors.INVALID_ICMPTYPE, str(self.name))
 
+    def __str__(self):
+        return 'icmp-type name="%s"' % (self.name)
+
 
 class Rich_Tcp_Mss_Clamp(_Rich_Element):
     def __init__(self, value):