You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: api_op_CreateSegment.go
    path of file: ./repos/aws-sdk-go-v2/service/evidently
    
    the code of the file until where you have to start completion: // Code generated by smithy-go-codegen DO NOT EDIT.

package evidently

import (
	"context"
	"fmt"
	awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
	"github.com/aws/aws-sdk-go-v2/service/evidently/types"
	"github.com/aws/smithy-go/middleware"
	smithyhttp "github.com/aws/smithy-go/transport/http"
)

// Use this operation to define a segment of your audience. A segment is a portion
// of your audience that share one or more characteristics. Examples could be
// Chrome browser users, users in Europe, or Firefox browser users in Europe who
// also fit other criteria that your application collects, such as age. Using a
// segment in an experiment limits that experiment to evaluate only the users who
// match the segment criteria. Using one or more segments in a launch allows you to
// define different traffic splits for the different audience segments. For more
// information about segment pattern syntax, see Segment rule pattern syntax (https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-Evidently-segments.html#CloudWatch-Evidently-segments-syntax.html)
// . The pattern that you define for a segment is matched against the value of
// evaluationContext , which is passed into Evidently in the EvaluateFeature (https://docs.aws.amazon.com/cloudwatchevidently/latest/APIReference/API_EvaluateFeature.html)
// operation, when Evidently assigns a feature variation to a user.
func (c *Client) CreateSegment(ctx context.Context, params *CreateSegmentInput, optFns ...func(*Options)) (*CreateSegmentOutput, error) {
	if params == nil {
		params = &CreateSegmentInput{}
	}

	result, metadata, err := c.invokeOperation(ctx, "CreateSegment", params, optFns, c.addOperationCreateSegmentMiddlewares)
	if err != nil {
		return nil, err
	}

	out := result.(*CreateSegmentOutput)
	out.ResultMetadata = metadata
	return out, nil
}

type CreateSegmentInput struct {

	// A name for the segment.
	//
	// This member is required.
	Name *string

	// The pattern to use for the segment. For more information about pattern syntax,
	// see Segment rule pattern syntax (https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudW
    
func (c *Client) addOperationCreateSegmentMiddlewares(stack *middleware.Stack, options Options) (err error) {
	if err := stack.Serialize.Add(&setOperationInputMiddleware{}, middleware.After); err != nil {
		return err
	}
	err = stack.Serialize.Add(&awsRestjson1_serializeOpCreateSegment{}, middleware.After)
	if err != nil {
		return err
	}
	err = stack.Deserialize.Add(&awsRestjson1_deserializeOpCreateSegment{}, middleware.After)
	if err != nil {
		return err
	}
	if err := addProtocolFinalizerMiddlewares(stack, options, "CreateSegment"); err != nil {
		return fmt.Errorf("add protocol finalizers: %v", err)
	}

	if err = addlegacyEndpointContextSetter(stack, options); err != nil {
		return err
	}
	if err = addSetLoggerMiddleware(stack, options); err != nil {
		return err
	}
	if err = addClientRequestID(stack); err != nil {
		return err
	}
	if err = addComputeContentLength(stack); err != nil {
		return err
	}
	if err = addResolveEndpointMiddleware(stack, options); err != nil {
		return err
	}
	if err = addComputePayloadSHA256(stack); err != nil {
		return err
	}
	if err = addRetry(stack, options); err != nil {
		return err
	}
	if err = addRawResponseToMetadata(stack); err != nil {
		return err
	}
	if err = addRecordResponseTiming(stack); err != nil {
		return err
	}
	if err = addClientUserAgent(stack, options); err != nil {
		return err
	}
	if err = smithyhttp.AddErrorCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = smithyhttp.AddCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = addSetLegacyContextSigningOptionsMiddleware(stack); err != nil {
		return err
	}
	if err = addOpCreateSegmentValidationMiddleware(stack); err != nil {
		return err
	}
	if err = stack.Initialize.Add(newServiceMetadataMiddleware_opCreateSegment(options.Region), middleware.Before); err != nil {
		return err
	}
	if err = addRecursionDetection(stack); err != nil {
		return err
	}
	if err = addRequestIDRetrieverMiddleware(stack); err != nil {
		return err
	}
	if err = addResponseErrorMiddleware(stack); err != nil {
		return err
	}
	if err = addRequestResponseLogging(stack, options); err != nil {
		return err
	}
	if err = addDisableHTTPSMiddleware(stack, options); err != nil {
		return err
	}
	return nil
}