private void decrementTargetAssignmentSize(String memberId) {
            MemberAssignmentData memberData = this.membersWithAssignmentSizes.get(memberId);
            if (memberData == null) {
                LOG.warn("Member Id {} not found", memberId);
                return;
            }

            if (memberData.currentAssignmentSize > 0) {
                memberData.currentAssignmentSize--;
            }
        }
@param memberId      The member Id.
Decrement the current target assignment size for the member, if it's assignment size is greater than zero.
group-coordinator/src/main/java/org/apache/kafka/coordinator/group/assignor/UniformHeterogeneousAssignmentBuilder.java