@Override
        public String toString() {
            return "TopicAssignmentState(" +
                    "topic=" + topic +
                    ", consumers=" + consumers +
                    ", partitionRacks=" + partitionRacks +
                    ", unassignedPartitions=" + unassignedPartitions +
                    ")";
        }
Performs range assignment of the specified partitions for the consumers with the provided subscriptions.
If rack-awareness is enabled for one or more consumers, we perform rack-aware assignment first to assign
the subset of partitions that can be aligned on racks, while retaining the same co-partitioning and
per-topic balancing guarantees as non-rack-aware range assignment. The remaining partitions are assigned
using standard non-rack-aware range assignment logic, which may result in mis-aligned racks.
clients/src/main/java/org/apache/kafka/clients/consumer/RangeAssignor.java