public Builder<T> copyExisting(boolean copyExisting) {
            this.copyExisting = copyExisting;
            return this;
        }
copy.existing

<p>Copy existing data from source collections and convert them to Change Stream events on
their respective topics. Any changes to the data that occur during the copy process are
applied once the copy is completed.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/mongodb-cdc/src/main/java/org/apache/inlong/sort/cdc/mongodb/MongoDBSource.java