def subscribe_to_shard(params = {}, options = {})
      params = params.dup
      output_event_stream_handler = _event_stream_handler(
        :output,
        params.delete(:output_event_stream_handler) || params.delete(:event_stream_handler),
        EventStreams::SubscribeToShardEventStream
      )

      yield(output_event_stream_handler) if block_given?

      req = build_request(:subscribe_to_shard, params)

      req.context[:output_event_stream_handler] = output_event_stream_handler
      req.handlers.add(Aws::Binary::DecodeHandler, priority: 95)

      req.send_request(options)
    end
def subscribe_to_shard(params = {}, options = {})
      params = params.dup
      output_event_stream_handler = _event_stream_handler(
        :output,
        params.delete(:output_event_stream_handler) || params.delete(:event_stream_handler),
        EventStreams::SubscribeToShardEventStream
      )

      yield(output_event_stream_handler) if block_given?

      req = build_request(:subscribe_to_shard, params)

      req.context[:output_event_stream_handler] = output_event_stream_handler
      req.handlers.add(Aws::Binary::DecodeHandler, priority: 95)

      req.send_request(options)
    end
@option options [required, Aws::CredentialProvider] :credentials
     Your AWS credentials. This can be an instance of any one of the
     following classes:

     * `Aws::Credentials` - Used for configuring static, non-refreshing
       credentials.

     * `Aws::InstanceProfileCredentials` - Used for loading credentials
       from an EC2 IMDS on an EC2 instance.

     * `Aws::SharedCredentials` - Used for loading credentials from a
       shared file, such as `~/.aws/config`.

     * `Aws::AssumeRoleCredentials` - Used when you need to assume a role.

     When `:credentials` are not configured directly, the following
     locations will be searched for credentials:

     * `Aws.config[:credentials]`
     * The `:access_key_id`, `:secret_access_key`, and `:session_token` options.
     * ENV['AWS_ACCESS_KEY_ID'], ENV['AWS_SECRET_ACCESS_KEY']
     * `~/.aws/credentials`
     * `~/.aws/config`
     * EC2 IMDS instance profile - When used by default, the timeouts are
       very aggressive. Construct and pass an instance of
       `Aws::InstanceProfileCredentails` to enable retries and extended
       timeouts.

   @option options [required, String] :region
     The AWS region to connect to.  The configured `:region` is
     used to determine the service `:endpoint`. When not passed,
     a default `:region` is search for in the following locations:

     * `Aws.config[:region]`
     * `ENV['AWS_REGION']`
     * `ENV['AMAZON_REGION']`
     * `ENV['AWS_DEFAULT_REGION']`
     * `~/.aws/credentials`
     * `~/.aws/config`

   @option options [String] :access_key_id

   @option options [Boolean] :convert_params (true)
     When `true`, an attempt is made to coerce request parameters into
     the required types.

   @option options [String] :endpoint
     The client endpoint is normally constructed from the `:region`
     option. You should only configure an `:endpoint` when connecting
     to test endpoints. This should be avalid HTTP(S) URI.

   @option options [Proc] :event_stream_handler
     When an EventStream or Proc object is provided, it will be used as callback for each chunk of event stream response received along the way.

   @option options [Proc] :input_event_stream_handler
     When an EventStream or Proc object is provided, it can be used for sending events for the event stream.

   @option options [Aws::Log::Formatter] :log_formatter (Aws::Log::Formatter.default)
     The log formatter.

   @option options [Symbol] :log_level (:info)
     The log level to send messages to the `:logger` at.

   @option options [Logger] :logger
     The Logger instance to send log messages to.  If this option
     is not set, logging will be disabled.

   @option options [Proc] :output_event_stream_handler
     When an EventStream or Proc object is provided, it will be used as callback for each chunk of event stream response received along the way.

   @option options [String] :profile ("default")
     Used when loading credentials from the shared credentials file
     at HOME/.aws/credentials.  When not specified, 'default' is used.

   @option options [Float] :retry_base_delay (0.3)
     The base delay in seconds used by the default backoff function.

   @option options [Symbol] :retry_jitter (:none)
     A delay randomiser function used by the default backoff function. Some predefined functions can be referenced by name - :none, :equal, :full, otherwise a Proc that takes and returns a number.

     @see https://www.awsarchitectureblog.com/2015/03/backoff.html

   @option options [Integer] :retry_limit (3)
     The maximum number of times to retry failed requests.  Only
     ~ 500 level server errors and certain ~ 400 level client errors
     are retried.  Generally, these are throttling errors, data
     checksum errors, networking errors, timeout errors and auth
     errors from expired credentials.

   @option options [Integer] :retry_max_delay (0)
     The maximum number of seconds to delay between retries (0 for no limit) used by the default backoff function.

   @option options [String] :secret_access_key

   @option options [String] :session_token

   @option options [Boolean] :simple_json (false)
     Disables request parameter conversion, validation, and formatting.
     Also disable response data type conversions. This option is useful
     when you want to ensure the highest level of performance by
     avoiding overhead of walking request parameters and response data
     structures.

     When `:simple_json` is enabled, the request parameters hash must
     be formatted exactly as the DynamoDB API expects.

   @option options [Boolean] :stub_responses (false)
     Causes the client to return stubbed responses. By default
     fake responses are generated and returned. You can specify
     the response data to return or errors to raise by calling
     {ClientStubs#stub_responses}. See {ClientStubs} for more information.

     ** Please note ** When response stubbing is enabled, no HTTP
     requests are made, and retries are disabled.

   @option options [Boolean] :validate_params (true)
     When `true`, request parameters are validated before
     sending the request.

 @!group API Operations
 Call this operation from your consumer after you call
 RegisterStreamConsumer to register the consumer with Kinesis Data
 Streams. If the call succeeds, your consumer starts receiving events
 of type SubscribeToShardEvent for up to 5 minutes, after which time
 you need to call `SubscribeToShard` again to renew the subscription if
 you want to continue to receive records.

 You can make one call to `SubscribeToShard` per second per
 `ConsumerARN`. If your call succeeds, and then you call the operation
 again less than 5 seconds later, the second call generates a
 ResourceInUseException. If you call the operation a second time more
 than 5 seconds after the first call succeeds, the second call succeeds
 and the first connection gets shut down.

 @option params [required, String] :consumer_arn
   For this parameter, use the value you obtained when you called
   RegisterStreamConsumer.

 @option params [required, String] :shard_id
   The ID of the shard you want to subscribe to. To see a list of all the
   shards for a given stream, use ListShards.

 @option params [required, Types::StartingPosition] :starting_position

 @return [Types::SubscribeToShardOutput] Returns a {Seahorse::Client::Response response} object which responds to the following methods:

   * {Types::SubscribeToShardOutput#event_stream #event_stream} => Types::SubscribeToShardEventStream

 @example EventStream Operation Example

   You can process event once it arrives immediately, or wait until
   full response complete and iterate through eventstream enumerator.

   To interact with event immediately, you need to register #subscribe_to_shard
   with callbacks, callbacks can be register for specifc events or for all events,
   callback for errors in the event stream is also available for register.

   Callbacks can be passed in by `:event_stream_handler` option or within block
   statement attached to #subscribe_to_shard call directly. Hybrid pattern of both
   is also supported.

   `:event_stream_handler` option takes in either Proc object or
   Aws::Kinesis::EventStreams::SubscribeToShardEventStream object.

   Usage pattern a): callbacks with a block attached to #subscribe_to_shard
     Example for registering callbacks for all event types and error event

     client.subscribe_to_shard( # params input# ) do |stream|
       stream.on_error_event do |event|
         # catch unmodeled error event in the stream
         raise event
         # => Aws::Errors::EventError
         # event.event_type => :error
         # event.error_code => String
         # event.error_message => String
       end

       stream.on_event do |event|
         # process all events arrive
         puts event.event_type
         ...
       end

     end

   Usage pattern b): pass in `:event_stream_handler` for #subscribe_to_shard

     1) create a Aws::Kinesis::EventStreams::SubscribeToShardEventStream object
     Example for registering callbacks with specific events

       handler = Aws::Kinesis::EventStreams::SubscribeToShardEventStream.new
       handler.on_subscribe_to_shard_event_event do |event|
         event # => Aws::Kinesis::Types::SubscribeToShardEvent
       end
       handler.on_resource_not_found_exception_event do |event|
         event # => Aws::Kinesis::Types::ResourceNotFoundException
       end
       handler.on_resource_in_use_exception_event do |event|
         event # => Aws::Kinesis::Types::ResourceInUseException
       end
       handler.on_kms_disabled_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSDisabledException
       end
       handler.on_kms_invalid_state_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSInvalidStateException
       end
       handler.on_kms_access_denied_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSAccessDeniedException
       end
       handler.on_kms_not_found_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSNotFoundException
       end
       handler.on_kms_opt_in_required_event do |event|
         event # => Aws::Kinesis::Types::KMSOptInRequired
       end
       handler.on_kms_throttling_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSThrottlingException
       end
       handler.on_internal_failure_exception_event do |event|
         event # => Aws::Kinesis::Types::InternalFailureException
       end

     client.subscribe_to_shard( # params input #, event_stream_handler: handler)

     2) use a Ruby Proc object
     Example for registering callbacks with specific events

     handler = Proc.new do |stream|
       stream.on_subscribe_to_shard_event_event do |event|
         event # => Aws::Kinesis::Types::SubscribeToShardEvent
       end
       stream.on_resource_not_found_exception_event do |event|
         event # => Aws::Kinesis::Types::ResourceNotFoundException
       end
       stream.on_resource_in_use_exception_event do |event|
         event # => Aws::Kinesis::Types::ResourceInUseException
       end
       stream.on_kms_disabled_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSDisabledException
       end
       stream.on_kms_invalid_state_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSInvalidStateException
       end
       stream.on_kms_access_denied_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSAccessDeniedException
       end
       stream.on_kms_not_found_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSNotFoundException
       end
       stream.on_kms_opt_in_required_event do |event|
         event # => Aws::Kinesis::Types::KMSOptInRequired
       end
       stream.on_kms_throttling_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSThrottlingException
       end
       stream.on_internal_failure_exception_event do |event|
         event # => Aws::Kinesis::Types::InternalFailureException
       end
     end

     client.subscribe_to_shard( # params input #, event_stream_handler: handler)

   Usage pattern c): hybird pattern of a) and b)

       handler = Aws::Kinesis::EventStreams::SubscribeToShardEventStream.new
       handler.on_subscribe_to_shard_event_event do |event|
         event # => Aws::Kinesis::Types::SubscribeToShardEvent
       end
       handler.on_resource_not_found_exception_event do |event|
         event # => Aws::Kinesis::Types::ResourceNotFoundException
       end
       handler.on_resource_in_use_exception_event do |event|
         event # => Aws::Kinesis::Types::ResourceInUseException
       end
       handler.on_kms_disabled_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSDisabledException
       end
       handler.on_kms_invalid_state_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSInvalidStateException
       end
       handler.on_kms_access_denied_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSAccessDeniedException
       end
       handler.on_kms_not_found_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSNotFoundException
       end
       handler.on_kms_opt_in_required_event do |event|
         event # => Aws::Kinesis::Types::KMSOptInRequired
       end
       handler.on_kms_throttling_exception_event do |event|
         event # => Aws::Kinesis::Types::KMSThrottlingException
       end
       handler.on_internal_failure_exception_event do |event|
         event # => Aws::Kinesis::Types::InternalFailureException
       end

     client.subscribe_to_shard( # params input #, event_stream_handler: handler) do |stream|
       stream.on_error_event do |event|
         # catch unmodeled error event in the stream
         raise event
         # => Aws::Errors::EventError
         # event.event_type => :error
         # event.error_code => String
         # event.error_message => String
       end
     end

   Besides above usage patterns for process events when they arrive immediately, you can also
   iterate through events after response complete.

   Events are available at resp.event_stream # => Enumerator
   For parameter input example, please refer to following request syntax

 @example Request syntax with placeholder values

   async_resp = async_client.subscribe_to_shard({
     consumer_arn: "ConsumerARN", # required
     shard_id: "ShardId", # required
     starting_position: { # required
       type: "AT_SEQUENCE_NUMBER", # required, accepts AT_SEQUENCE_NUMBER, AFTER_SEQUENCE_NUMBER, TRIM_HORIZON, LATEST, AT_TIMESTAMP
       sequence_number: "SequenceNumber",
       timestamp: Time.now,
     },
   })
   # => Seahorse::Client::AsyncResponse
   async_resp.wait
   # => Seahorse::Client::Response
   # Or use async_resp.join!

 @example Response structure

   All events are available at resp.event_stream:
   resp.event_stream #=> Enumerator
   resp.event_stream.event_types #=> [:subscribe_to_shard_event, :resource_not_found_exception, :resource_in_use_exception, :kms_disabled_exception, :kms_invalid_state_exception, :kms_access_denied_exception, :kms_not_found_exception, :kms_opt_in_required, :kms_throttling_exception, :internal_failure_exception]

   For :subscribe_to_shard_event event available at #on_subscribe_to_shard_event_event callback and response eventstream enumerator:
   event.records #=> Array
   event.records[0].sequence_number #=> String
   event.records[0].approximate_arrival_timestamp #=> Time
   event.records[0].data #=> String
   event.records[0].partition_key #=> String
   event.records[0].encryption_type #=> String, one of "NONE", "KMS"
   event.continuation_sequence_number #=> String
   event.millis_behind_latest #=> Integer

   For :resource_not_found_exception event available at #on_resource_not_found_exception_event callback and response eventstream enumerator:
   event.message #=> String

   For :resource_in_use_exception event available at #on_resource_in_use_exception_event callback and response eventstream enumerator:
   event.message #=> String

   For :kms_disabled_exception event available at #on_kms_disabled_exception_event callback and response eventstream enumerator:
   event.message #=> String

   For :kms_invalid_state_exception event available at #on_kms_invalid_state_exception_event callback and response eventstream enumerator:
   event.message #=> String

   For :kms_access_denied_exception event available at #on_kms_access_denied_exception_event callback and response eventstream enumerator:
   event.message #=> String

   For :kms_not_found_exception event available at #on_kms_not_found_exception_event callback and response eventstream enumerator:
   event.message #=> String

   For :kms_opt_in_required event available at #on_kms_opt_in_required_event callback and response eventstream enumerator:
   event.message #=> String

   For :kms_throttling_exception event available at #on_kms_throttling_exception_event callback and response eventstream enumerator:
   event.message #=> String

   For :internal_failure_exception event available at #on_internal_failure_exception_event callback and response eventstream enumerator:
   event.message #=> String

 @see http://docs.aws.amazon.com/goto/WebAPI/kinesis-2013-12-02/SubscribeToShard AWS API Documentation

 @overload subscribe_to_shard(params = {})
 @param [Hash] params ({})