the extractor that provides a value in the form of any numeric object or
the name of the method that could be invoked via Java reflection and that
returns numeric values to aggregate; this parameter can also be a dot-delimited
sequence of method names which would result in an aggregator based on the
ChainedExtractor that is based on an array of corresponding
UniversalExtractor objects. May not be null
Protected @classServer-side EntryAggregator implementation type identifier.
Protected Optional extractorThe ValueExtractor to apply when aggregating results.
Returns a CompositeAggregator comprised of this and the provided aggregator.
a CompositeAggregator comprised of this and the provided aggregator
the next aggregator
Calculates a sum for values of any numeric type extracted from a set of entries in a Map in a form of a numeric value.
If the set of entries is empty, a 'null' result is returned.