def stub_responses(operation_name, *stubs)
      if config.stub_responses
        apply_stubs(operation_name, stubs.flatten)
      else
        msg = 'stubbing is not enabled; enable stubbing in the constructor '
        msg << 'with `:stub_responses => true`'
        raise msg
      end
    end
def stub_responses(operation_name, *stubs)
      if config.stub_responses
        apply_stubs(operation_name, stubs.flatten)
      else
        msg = 'stubbing is not enabled; enable stubbing in the constructor '
        msg << 'with `:stub_responses => true`'
        raise msg
      end
    end
Configures what data / errors should be returned from the named operation
 when response stubbing is enabled.

 ## Basic usage

 When you enable response stubbing, the client will generate fake
 responses and will not make any HTTP requests.

     client = Aws::S3::Client.new(stub_responses: true)
     client.list_buckets
     #=> #<struct Aws::S3::Types::ListBucketsOutput buckets=[], owner=nil>

 You can provide stub data that will be returned by the client.

     # stub data in the constructor
     client = Aws::S3::Client.new(stub_responses: {
       list_buckets: { buckets: [{name: 'my-bucket' }] },
       get_object: { body: 'data' },
     })

     client.list_buckets.buckets.map(&:name) #=> ['my-bucket']
     client.get_object(bucket:'name', key:'key').body.read #=> 'data'

 You can also specify the stub data using {#stub_responses}

     client = Aws::S3::Client.new(stub_responses: true)
     client.stub_responses(:list_buckets, {
       buckets: [{ name: 'my-bucket' }]
     })

     client.list_buckets.buckets.map(&:name)
     #=> ['my-bucket']

 With a Resource class {#stub_responses} on the corresponding client:

     s3 = Aws::S3::Resource.new(stub_responses: true)
     s3.client.stub_responses(:list_buckets, {
       buckets: [{ name: 'my-bucket' }]
     })

     s3.buckets.map(&:name)
     #=> ['my-bucket']

 Lastly, default stubs can be configured via `Aws.config`:

     Aws.config[:s3] = {
       stub_responses: {
         list_buckets: { buckets: [{name: 'my-bucket' }] }
       }
     }

     Aws::S3::Client.new.list_buckets.buckets.map(&:name)
     #=> ['my-bucket']

     Aws::S3::Resource.new.buckets.map(&:name)
     #=> ['my-bucket']

 ## Dynamic Stubbing

 In addition to creating static stubs, it's also possible to generate
 stubs dynamically based on the parameters with which operations were
 called, by passing a `Proc` object:

     s3 = Aws::S3::Resource.new(stub_responses: true)
     s3.client.stub_responses(:put_object, -> (context) {
       s3.client.stub_responses(:get_object, content_type: context.params[:content_type])
     })

 The yielded object is an instance of {Seahorse::Client::RequestContext}.

 ## Stubbing Errors

 When stubbing is enabled, the SDK will default to generate
 fake responses with placeholder values. You can override the data
 returned. You can also specify errors it should raise.

     # simulate service errors, give the error code
     client.stub_responses(:get_object, 'NotFound')
     client.get_object(bucket:'aws-sdk', key:'foo')
     #=> raises Aws::S3::Errors::NotFound

     # to simulate other errors, give the error class, you must
     # be able to construct an instance with `.new`
     client.stub_responses(:get_object, Timeout::Error)
     client.get_object(bucket:'aws-sdk', key:'foo')
     #=> raises new Timeout::Error

     # or you can give an instance of an error class
     client.stub_responses(:get_object, RuntimeError.new('custom message'))
     client.get_object(bucket:'aws-sdk', key:'foo')
     #=> raises the given runtime error object

 ## Stubbing HTTP Responses

 As an alternative to providing the response data, you can provide
 an HTTP response.

     client.stub_responses(:get_object, {
       status_code: 200,
       headers: { 'header-name' => 'header-value' },
       body: "...",
     })

 To stub a HTTP response, pass a Hash with all three of the following
 keys set:

 * **`:status_code`** - <Integer> - The HTTP status code
 * **`:headers`** - Hash<String,String> - A hash of HTTP header keys and values
 * **`:body`** - <String,IO> - The HTTP response body.

 ## Stubbing Multiple Responses

 Calling an operation multiple times will return similar responses.
 You can configure multiple stubs and they will be returned in sequence.

     client.stub_responses(:head_object, [
       'NotFound',
       { content_length: 150 },
     ])

     client.head_object(bucket:'aws-sdk', key:'foo')
     #=> raises Aws::S3::Errors::NotFound

     resp = client.head_object(bucket:'aws-sdk', key:'foo')
     resp.content_length #=> 150

 @param [Symbol] operation_name

 @param [Mixed] stubs One or more responses to return from the named
   operation.

 @return [void]

 @raise [RuntimeError] Raises a runtime error when called
   on a client that has not enabled response stubbing via
   `:stub_responses => true`.