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| <html> |
| <h2>CoGroupByKey</h2> |
| <p>CoGroupByKey performs a relational join of two or more key/value PCollections that have the same key type.</p> |
| <p>In this task, we are going to implement a |
| <a href="https://beam.apache.org/releases/javadoc/2.11.0/org/apache/beam/sdk/transforms/join/CoGroupByKey.html"> |
| CoGroupByKey</a> transform that join words by its first alphabetical letter, and then produces the toString() |
| representation of the WordsAlphabet model. |
| </p> |
| <br> |
| <br> |
| <div class='hint'>Refer to <a href="https://beam.apache.org/releases/javadoc/2.11.0/org/apache/beam/sdk/transforms/join/CoGroupByKey.html">CoGroupByKey</a>, |
| <a href="https://beam.apache.org/releases/javadoc/2.11.0/org/apache/beam/sdk/values/TupleTag.html">TupleTag</a>, |
| and <a href="https://beam.apache.org/releases/javadoc/2.11.0/org/apache/beam/sdk/transforms/join/CoGbkResult.html">CoGbkResult</a>.</div> |
| </html> |
