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Attempting to call the partition method in the DefaultPartitioner will throw an error, as this method will be deprecated and no longer return a partition. computePartition has replaced its functionality. 

/**
 * Indicates calling a deprecated method. The method is no longer supported and does not perform the function
 * it once did. This is a fatal error as this method is not intended to be called and undesired behavior will result.
 */
public class UnsupportedMethodException extends ApiException

Proposed Changes

Change the behavior of the default partitioner in the no explicit partition, key = null case. Choose the “sticky” partition for the given topic. The “sticky” partition is changed when the record accumulator is allocating a new batch for a topic on a given partition.

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