* reader.setQuery(QueryBuilders.termQuery("field", "value")); // Set a query
 *
 * Map<String, Object> document;
 * while ((document = reader.read()) != null) {
 *     // Process the document
 *     System.out.println(document);
 * }
 *
 * reader.close(); // Close the reader to release resources
 * }
 * </pre>
 */
public class ESSourceReader implements DocumentReader {

        ParserRequest parserRequest = mock(ParserRequest.class);
        Logger logger = mock(Logger.class);

        // Capture error messages for debugging
        doAnswer(invocation -> {
                    System.err.println("[ERROR] " + invocation.getArgument(0));
                    return null;
                })
                .when(logger)
                .error(anyString());

            t.printStackTrace(pw);
            pw.flush();
            return systemHelper.abbreviateLongText(sw.toString());
        } catch (final IOException e) {
            logger.warn("Failed to print the stack trace {}", t.getMessage(), e);
        }
        return StringUtil.EMPTY;
    }

    assertEquals(0, ArbitraryInstances.get(FloatBuffer.class).capacity());
    assertEquals(0, ArbitraryInstances.get(DoubleBuffer.class).capacity());
    ArbitraryInstances.get(PrintStream.class).println("test");
    ArbitraryInstances.get(PrintWriter.class).println("test");
    assertThat(ArbitraryInstances.get(File.class)).isNotNull();
    assertFreshInstanceReturned(
        ByteArrayOutputStream.class, OutputStream.class,

2018/12/26 17:49:36 listening on http://localhost:8888/
```

This will open the login page of keycloak, upon successful login, STS credentials along with any buckets discovered using the credentials will be printed on the screen, for example:

```
{
  "buckets": [
    "bucket-x"
  ],
  "credentials": {
    "AccessKeyID": "6N2BALX7ELO827DXS3GK",
    "SecretAccessKey": "23JKqAD+um8ObHqzfIh+bfqwG9V8qs9tFY6MqeFR+xxx",

      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

   Copyright [yyyy] [name of copyright owner]

   Licensed under the Apache License, Version 2.0 (the "License");

      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

   Copyright [yyyy] [name of copyright owner]

   Licensed under the Apache License, Version 2.0 (the "License");

      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

   Copyright [yyyy] [name of copyright owner]

   Licensed under the Apache License, Version 2.0 (the "License");

      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

   Copyright [yyyy] [name of copyright owner]

   Licensed under the Apache License, Version 2.0 (the "License");

      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

   Copyright [yyyy] [name of copyright owner]

   Licensed under the Apache License, Version 2.0 (the "License");