code: private static AttributeKey getAttributeKey(final String schemaArn, final String facetName, final String attributeName) {
          return new AttributeKey().withFacetName(facetName).withSchemaArn(schemaArn).withName(attributeName);
      }
docs: Gets attribute key.
  
  @param schemaArn     the schema arn
  @param facetName     the facet name
  @param attributeName the attribute name
  @return the attribute key