@Override
    public DescribeInstancesResult describeInstances(DescribeInstancesRequest request) {
        request = beforeClientExecution(request);
        return executeDescribeInstances(request);
    }
<p>
Retrieves information about the EC2 instances in an Amazon GameLift managed fleet, including instance ID,
connection data, and status. You can use this operation with a multi-location fleet to get location-specific
instance information. As an alternative, use the operations <a>ListCompute</a> and <a>DescribeCompute</a> to
retrieve information for compute resources, including EC2 and Anywhere fleets.
</p>
<p>
You can call this operation in the following ways:
</p>
<ul>
<li>
<p>
To get information on all instances in a fleet's home Region, specify the fleet ID.
</p>
</li>
<li>
<p>
To get information on all instances in a fleet's remote location, specify the fleet ID and location name.
</p>
</li>
<li>
<p>
To get information on a specific instance in a fleet, specify the fleet ID and instance ID.
</p>
</li>
</ul>
<p>
Use the pagination parameters to retrieve results as a set of sequential pages.
</p>
<p>
If successful, this operation returns <code>Instance</code> objects for each requested instance, listed in no
particular order. If you call this operation for an Anywhere fleet, you receive an InvalidRequestException.
</p>
<p>
<b>Learn more</b>
</p>
<p>
<a href="https://docs.aws.amazon.com/gamelift/latest/developerguide/fleets-remote-access.html">Remotely connect
to fleet instances</a>
</p>
<p>
<a href="https://docs.aws.amazon.com/gamelift/latest/developerguide/fleets-creating-debug.html">Debug fleet
issues</a>
</p>
<p>
<b>Related actions</b>
</p>
<p>
<a href=
"https://docs.aws.amazon.com/gamelift/latest/developerguide/reference-awssdk.html#reference-awssdk-resources-fleets"
>All APIs by task</a>
</p>

@param describeInstancesRequest
@return Result of the DescribeInstances operation returned by the service.
@throws UnauthorizedException
        The client failed authentication. Clients should not retry such requests.
@throws InvalidRequestException
        One or more parameter values in the request are invalid. Correct the invalid parameter values before
        retrying.
@throws NotFoundException
        THe requested resources was not found. The resource was either not created yet or deleted.
@throws InternalServiceException
        The service encountered an unrecoverable internal failure while processing the request. Clients can retry
        such requests immediately or after a waiting period.
@throws UnsupportedRegionException
        The requested operation is not supported in the Region specified.
@sample AmazonGameLift.DescribeInstances
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/gamelift-2015-10-01/DescribeInstances" target="_top">AWS API
     Documentation</a>
aws-java-sdk-gamelift/src/main/java/com/amazonaws/services/gamelift/AmazonGameLiftClient.java