code: func (r Billing_Invoice) GetTaxInfo() (resp datatypes.Billing_Invoice_Tax_Info, err error) {
  	err = r.Session.DoRequest("SoftLayer_Billing_Invoice", "getTaxInfo", nil, &r.Options, &resp)
  	return
  }
docs: // Retrieve This is the tax information that applies to tax auditing. This is the official tax record for this invoice.