Refreshing website content from main repo.

  Source commit:
  OpenLineage/OpenLineage@50ba05b

docs/integrations/spark/spark_column_lineage.md

@@ -92,46 +92,3 @@ To unravel two dependencies implement following logic:
 
 The inputs are also mapped for all dataset dependencies. The result is added to each output. 
 Finally, the list of outputs with all their inputs is mapped to `ColumnLineageDatasetFacetFields` object.
-
-## Writing custom extensions
-
-Spark framework is known for its great ability to be extended by custom libraries capable of reading or writing to anything. In case of having a custom implementation, we prepared an ability to extend column-level lineage implementation to be able to retrieve information from other input or output LogicalPlan nodes. 
-
-Creating such an extension requires implementing a following interface: 
-
-```
-/** Interface for implementing custom collectors of column-level lineage. */
-interface CustomColumnLineageVisitor {
-
-  /**
-   * Collect inputs for a given {@link LogicalPlan}. Column-level lineage mechanism traverses
-   * LogicalPlan on its node. This method will be called for each traversed node. Input information
-   * should be put into builder.
-   *
-   * @param node
-   * @param builder
-   */
-  void collectInputs(LogicalPlan node, ColumnLevelLineageBuilder builder);
-
-  /**
-   * Collect outputs for a given {@link LogicalPlan}. Column-level lineage mechanism traverses
-   * LogicalPlan on its node. This method will be called for each traversed node. Output information
-   * should be put into builder.
-   *
-   * @param node
-   * @param builder
-   */
-  void collectOutputs(LogicalPlan node, ColumnLevelLineageBuilder builder);
-
-  /**
-   * Collect expressions for a given {@link LogicalPlan}. Column-level lineage mechanism traverses
-   * LogicalPlan on its node. This method will be called for each traversed node. Expression
-   * dependency information should be put into builder.
-   *
-   * @param node
-   * @param builder
-   */
-  void collectExpressionDependencies(LogicalPlan node, ColumnLevelLineageBuilder builder);
-}
-```
-and making it available for Service Loader (implementation class name has to be put in a resource file `META-INF/services/io.openlineage.spark.agent.lifecycle.plan.column.CustomColumnLineageVisitor`).