Optional
This field must only be used when "expression" is chosen as the License object has its own acknowledgement.
from field: optional cyclonedx.v1_6.LicenseAcknowledgementEnumeration acknowledgement = 3;
from oneof cyclonedx.v1_6.LicenseChoice.choice
from message cyclonedx.v1_6.LicenseChoice
This field must only be used when "expression" is chosen as the License object has its own acknowledgement.