If a processor or agent does an explicit operation on
existing elements.
Values:
OPERATION_TYPE_UNSPECIFIED (0):
Operation type unspecified. If no operation is specified a
provenance entry is simply used to match against a
parent.
ADD (1):
Add an element.
REMOVE (2):
Remove an element identified by parent.
UPDATE (7):
Updates any fields within the given
provenance scope of the message. It 'overwrites'
the fields rather than replacing them. This is
especially relevant when we just want to update
a field value of an entity without also
affecting all the child properties.
REPLACE (3):
Currently unused. Replace an element identified by
parent.
EVAL_REQUESTED (4):
Deprecated. Request human review for the element identified
by parent.
EVAL_APPROVED (5):
Deprecated. Element is reviewed and approved
at human review, confidence will be set to 1.0.
EVAL_SKIPPED (6):
Deprecated. Element is skipped in the
validation process.