code: func (r Account) LinkExternalAccount(externalAccountId *string, authorizationToken *string, externalServiceProviderKey *string) (err error) {
  	var resp datatypes.Void
  	params := []interface{}{
  		externalAccountId,
  		authorizationToken,
  		externalServiceProviderKey,
  	}
  	err = r.Session.DoRequest("SoftLayer_Account", "linkExternalAccount", params, &r.Options, &resp)
  	return
  }
docs: // This method will link this SoftLayer account with the provided external account.