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: anchore_client.go
    path of file: ./repos/pipeline/internal/security
    
    the code of the file until where you have to start completion: // Copyright Â© 2019 Banzai Cloud
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is 
    
func (a anchoreClient) GetUser(ctx context.Context, userName string) (interface{}, error) {
	fnCtx := map[string]interface{}{"userName": userName}
	a.logger.Info("retrieving anchore user", fnCtx)

	usr, resp, err := a.getRestClient().UserManagementApi.GetAccountUserExecute(
		a.getRestClient().UserManagementApi.GetAccountUser(a.authorizedContext(ctx), userName, userName),
	)
	if err != nil && resp == nil { // TODO: simplify error checking (openapi returns a generic error for 404 as well)
		a.logger.Debug("failed to retrieve user from anchore", fnCtx)

		return nil, errors.WrapIfWithDetails(err, "failed to retrieve user from anchore", fnCtx)
	}

	if resp.StatusCode == http.StatusNotFound {
		// user not found
		return nil, nil
	}

	if err != nil {
		a.logger.Debug("failed to retrieve user from anchore", fnCtx)

		return nil, errors.WrapIfWithDetails(err, "failed to retrieve user from anchore", fnCtx)
	}

	return usr, nil
}