public TargetAssignmentBuilder<T> withTargetAssignment(
        Map<String, Assignment> targetAssignment
    ) {
        this.targetAssignment = targetAssignment;
        return this;
    }
Adds the existing target assignment.

@param targetAssignment   The existing target assignment.
@return This object.
group-coordinator/src/main/java/org/apache/kafka/coordinator/group/modern/TargetAssignmentBuilder.java