operator property
Defines how the dimensionValues of a dimension are interpreted.
For example, for dimension type TOPIC_FILTER, the IN operator,
a message will be counted only if its topic matches one of the topic
filters. With NOT_IN operator, a message will be counted only
if it doesn't match any of the topic filters. The operator is optional: if
it's not provided (is null), it will be interpreted as
IN.
Implementation
final DimensionValueOperator? operator;