<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_feature_permission(request, feature, operation=None):
 """Check if a feature-specific field can be displayed. This method check a permission for a feature-specific field. Such field is usually provided through Neutron extension. :param request: Request Object :param feature: feature name defined in FEATURE_MAP :param operation (optional):
 Operation type. The valid value should be defined in FEATURE_MAP[feature]['policies'] It must be specified if FEATURE_MAP[feature] has 'policies'. """

    network_config = getattr(settings, 'OPENSTACK_NEUTRON_NETWORK', {})
    feature_info = FEATURE_MAP.get(feature)
    if not feature_info:
        raise ValueError("The requested feature '%(feature)s' is unknown. "
                         "Please make sure to specify a feature defined "
                         "in FEATURE_MAP.")

    # Check dashboard settings
    feature_config = feature_info.get('config')
    if feature_config:
        if not network_config.get(feature_config['name'],
                                  feature_config['default']):
            return False

    # Check policy
    feature_policies = feature_info.get('policies')
    if feature_policies:
        policy_name = feature_policies.get(operation)
        if not policy_name:
            raise ValueError("The 'operation' parameter for "
                             "get_feature_permission '%(feature)s' "
                             "is invalid. It should be one of %(allowed)s"
                             % {'feature': feature,
                                'allowed': ' '.join(feature_policies.keys())})
        role = (('network', policy_name),)
        if not policy.check(role, request):
            return False

    # Check if a required extension is enabled
    feature_extension = feature_info.get('extension')
    if feature_extension:
        try:
            return is_extension_supported(request, feature_extension)
        except Exception:
            LOG.info("Failed to check Neutron '%s' extension is not supported",
                     feature_extension)
            return False

    # If all checks are passed, now a given feature is allowed.
    return True