boardingPolicy property
Indicates the policy the airline uses for boarding.
If unset, Google will default to zoneBased.
Possible string values are:
- "BOARDING_POLICY_UNSPECIFIED"
 - "ZONE_BASED"
 - "zoneBased" : Legacy alias for 
ZONE_BASED. Deprecated. - "GROUP_BASED"
 - "groupBased" : Legacy alias for 
GROUP_BASED. Deprecated. - "BOARDING_POLICY_OTHER"
 - "boardingPolicyOther" : Legacy alias for 
BOARDING_POLICY_OTHER. Deprecated. 
Implementation
core.String? boardingPolicy;