revert remove not used internal func

pkg/netpol/internal/common/connectionset.go

@@ -171,6 +171,26 @@ func (conn *ConnectionSet) Contains(port, protocol string) bool {
 	return false
 }
 
+// ContainedIn returns true if current ConnectionSet is contained in the input ConnectionSet object
+func (conn *ConnectionSet) ContainedIn(other *ConnectionSet) bool {
+	if other.AllowAll {
+		return true
+	}
+	if conn.AllowAll {
+		return false
+	}
+	for protocol, ports := range conn.AllowedProtocols {
+		otherPorts, ok := other.AllowedProtocols[protocol]
+		if !ok {
+			return false
+		}
+		if !ports.ContainedIn(otherPorts) {
+			return false
+		}
+	}
+	return true
+}
+
 // AddConnection updates current ConnectionSet object with new allowed connection
 func (conn *ConnectionSet) AddConnection(protocol v1.Protocol, ports *PortSet) {
 	if ports.IsEmpty() {