<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def has_firewall(vlan):
 """Helper to determine whether or not a VLAN has a firewall. :param dict vlan: A dictionary representing a VLAN :returns: True if the VLAN has a firewall, false if it doesn't. """

    return bool(
        vlan.get('dedicatedFirewallFlag', None) or
        vlan.get('highAvailabilityFirewallFlag', None) or
        vlan.get('firewallInterfaces', None) or
        vlan.get('firewallNetworkComponents', None) or
        vlan.get('firewallGuestNetworkComponents', None)
    )