@SdkInternalApi
    final GetIntrospectionSchemaResult executeGetIntrospectionSchema(GetIntrospectionSchemaRequest getIntrospectionSchemaRequest) {

        ExecutionContext executionContext = createExecutionContext(getIntrospectionSchemaRequest);
        AWSRequestMetrics awsRequestMetrics = executionContext.getAwsRequestMetrics();
        awsRequestMetrics.startEvent(Field.ClientExecuteTime);
        Request<GetIntrospectionSchemaRequest> request = null;
        Response<GetIntrospectionSchemaResult> response = null;

        try {
            awsRequestMetrics.startEvent(Field.RequestMarshallTime);
            try {
                request = new GetIntrospectionSchemaRequestProtocolMarshaller(protocolFactory).marshall(super.beforeMarshalling(getIntrospectionSchemaRequest));
                // Binds the request metrics to the current request.
                request.setAWSRequestMetrics(awsRequestMetrics);
                request.addHandlerContext(HandlerContextKey.CLIENT_ENDPOINT, endpoint);
                request.addHandlerContext(HandlerContextKey.ENDPOINT_OVERRIDDEN, isEndpointOverridden());
                request.addHandlerContext(HandlerContextKey.SIGNING_REGION, getSigningRegion());
                request.addHandlerContext(HandlerContextKey.SERVICE_ID, "AppSync");
                request.addHandlerContext(HandlerContextKey.OPERATION_NAME, "GetIntrospectionSchema");
                request.addHandlerContext(HandlerContextKey.ADVANCED_CONFIG, advancedConfig);

            } finally {
                awsRequestMetrics.endEvent(Field.RequestMarshallTime);
            }

            HttpResponseHandler<AmazonWebServiceResponse<GetIntrospectionSchemaResult>> responseHandler = protocolFactory.createResponseHandler(
                    new JsonOperationMetadata().withPayloadJson(false).withHasStreamingSuccessResponse(false),
                    new GetIntrospectionSchemaResultJsonUnmarshaller());
            response = invoke(request, responseHandler, executionContext);

            return response.getAwsResponse();

        } finally {

            endClientExecution(awsRequestMetrics, request, response);
        }
    }
<p>
Retrieves the introspection schema for a GraphQL API.
</p>

@param getIntrospectionSchemaRequest
@return Result of the GetIntrospectionSchema operation returned by the service.
@throws GraphQLSchemaException
        The GraphQL schema is not valid.
@throws NotFoundException
        The resource specified in the request was not found. Check the resource, and then try again.
@throws UnauthorizedException
        You aren't authorized to perform this operation.
@throws InternalFailureException
        An internal AppSync error occurred. Try your request again.
@sample AWSAppSync.GetIntrospectionSchema
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/appsync-2017-07-25/GetIntrospectionSchema" target="_top">AWS
     API Documentation</a>
aws-java-sdk-appsync/src/main/java/com/amazonaws/services/appsync/AWSAppSyncClient.java