// TODO(cgdecker): Add CharSource.slice?
    StringBuilder builder = new StringBuilder();
    Reader reader = concatenated.openStream(); // no need to worry about closing
    for (int i = 0; i < 8; i++) {
      builder.append((char) reader.read());
    }
    assertEquals(expected, builder.toString());
  }

if __name__ == '__main__':
	app.run()
```

When you're writing a Lambda function for use with MinIO, the function is based on event context that MinIO provides to the Lambda function. The event context provides information about the request being made. It contains the parameters with relevant context. The fields used to create the Lambda function are as follows:

  //    the initial write (just stronger guarantees if it does).
  //
  // See: http://cs.oswego.edu/pipermail/concurrency-interest/2015-January/013800.html
  // For a (long) discussion about this specific issue and the general futility of life.
  //
  // For the time being we are OK with the problem discussed above since it requires a caller to

            // the cancelled task's executor to run the noop AsyncCallable.
            //
            // ---
            //
            // If the CAS fails, the provided callable already started running (or it is about
            // to). Our contract promises:
            //
            // 1. not to execute a new callable until the old one has returned
            //

  //   completion preferably and AQS is non-deterministic (depends on where in the queue the waiter
  //   is). If we wanted to be strict about it, we could store the unpark() time in the Waiter node
  //   and we could use that to make a decision about whether or not we timed out prior to being
  //   unparked.

  @SuppressWarnings({
    "LabelledBreakTarget", // TODO(b/345814817): Maybe fix?

    // TODO(dbeaumont): Support escapers where alphanumeric chars are not safe.
    checkNotNull(safeChars); // eager for GWT.
    // Avoid any misunderstandings about the behavior of this escaper
    if (safeChars.matches(".*[0-9A-Za-z].*")) {
      throw new IllegalArgumentException(
          "Alphanumeric characters are always 'safe' and should not be explicitly specified");
    }

        writeInt2(andxOffset, dst, start + ANDX_OFFSET_OFFSET);

        andx.useUnicode = useUnicode;
        if (andx instanceof AndXServerMessageBlock) {

            /*
             * A word about communicating header info to andx smbs
             *
             * This is where we recursively invoke the provided andx smb
             * object to write it's parameter words and bytes to our outgoing

 * general way.
 *
 * <p>A good example of usage of this class is for HTML escaping where the replacement array
 * contains information about the named HTML entities such as {@code &amp;} and {@code &quot;} while
 * {@link #escapeUnsafe} is overridden to handle general escaping of the form {@code &#NNNNN;}.
 *

        // it refers to a snapshot artifact or meta-version.
        // NOTE: Release metadata includes version information about artifacts that have been released, to allow
        // meta-versions like RELEASE and LATEST to resolve, and also to allow retrieval of the range of valid, released
        // artifacts available.

	"Action": "s3:ListBucket*",
	"Resource": "arn:aws:s3:::mybucket",
	"Condition": {"IpAddress": {"aws:SourceIp": "203.0.113.0/24"}}
  }
}
```

- `aws:UserAgent` - This value is a string that contains information about the requester's client application. This string is generated by the client and can be unreliable. You can only use this context key from `mc` or other MinIO SDKs which standardize the User-Agent string.