assertThat(transformation.inverse().inverse()).isSameInstanceAs(transformation);
  }

  /**
   * Asserts that {@code transformation} behaves as expected for {@link
   * LinearTransformation#forNaN}.
   */
  static void assertLinearTransformationNaN(LinearTransformation transformation) {
    assertThat(transformation.isHorizontal()).isFalse();

    }

    /**
     * Returns the transformation.
     *
     * @return the transformation
     */
    public String getTransformation() {
        return transformation;
    }

    /**
     * Sets the transformation.
     *
     * @param transformation
     *            the transformation
     */
    public void setTransformation(final String transformation) {

            getDataCallCount.set(0);
            lastResponseData = null;
            lastAccessResultData = null;
        }
    }

    /**
     * Transformer implementation that performs content transformation
     */
    public static class ContentTransformer implements Transformer {
        private final String name;
        private final Map<String, String> transformationRules = new HashMap<>();

/**
 * Implementation of IndexUpdateCallback for handling document indexing operations.
 * This class manages the process of updating the search index with documents from
 * data stores, including bulk operations, document transformation, and error handling.
 */
public class IndexUpdateCallbackImpl implements IndexUpdateCallback {
    private static final Logger logger = LogManager.getLogger(IndexUpdateCallbackImpl.class);

    /**

        int keyLength = getKeyLength();
        String transformation;

        // Select appropriate AES algorithm based on key length
        if (keyLength == 32) {
            // AES-256 support
            transformation = "AES/GCM/NoPadding";
        } else if (keyLength == 16) {
            // AES-128 (existing)
            transformation = "AES/GCM/NoPadding";
        } else {

- **Popular Words Analytics**: Track and analyze frequently searched terms
- **Flexible Text Processing**: Configurable converters and normalizers for text transformation
- **OpenSearch Integration**: Seamless integration with OpenSearch/Elasticsearch clusters
- **Asynchronous Operations**: Non-blocking suggestion requests with callback support

      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.

        ensurePositive(xSumOfSquaresOfDeltas * ySumOfSquaresOfDeltas);
    return ensureInUnitRange(sumOfProductsOfDeltas / Math.sqrt(productOfSumsOfSquaresOfDeltas));
  }

  /**
   * Returns a linear transformation giving the best fit to the data according to <a
   * href="http://mathworld.wolfram.com/LeastSquaresFitting.html">Ordinary Least Squares linear

      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.

      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.