code: func (c *Client) ListCodesOfConduct(ctx context.Context) ([]*CodeOfConduct, *Response, error) {
  	req, err := c.NewRequest("GET", "codes_of_conduct", nil)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	// TODO: remove custom Accept header when this API fully launches.
  	req.Header.Set("Accept", mediaTypeCodesOfConductPreview)
  
  	var cs []*CodeOfConduct
  	resp, err := c.Do(ctx, req, &cs)
  	if err != nil {
  		return nil, resp, err
  	}
  
  	return cs, resp, nil
  }
docs: // ListCodesOfConduct returns all codes of conduct.
  //
  // GitHub API docs: https://developer.github.com/v3/codes_of_conduct/#list-all-codes-of-conduct