func (c *API) GetContact(contactId string) (data GetContactResponse, err error) {
	endpoint := zoho.Endpoint{
		Name:         InvoicesModule,
		URL:          fmt.Sprintf("https://invoice.zoho.%s/api/v3/%s/%s", c.ZohoTLD, ContactsModule, contactId),
		Method:       zoho.HTTPGet,
		ResponseData: &GetContactResponse{},
		URLParameters: map[string]zoho.Parameter{
			"filter_by": "",
		},
		BodyFormat: zoho.JSON_STRING,
		Headers: map[string]string{
			InvoiceAPIEndpointHeader: c.OrganizationID,
		},
	}
	err = c.Zoho.HTTPRequest(&endpoint)
	if err != nil {
		return GetContactResponse{}, fmt.Errorf("Failed to retrieve contact: %s", err)
	}
	if v, ok := endpoint.ResponseData.(*GetContactResponse); ok {
		if v.Code != 0 {
			return *v, fmt.Errorf("Failed to retrieve contact: %s", v.Message)
		}
		return *v, nil
	}
	return GetContactResponse{}, fmt.Errorf("Data retrieved was not 'GetContactResponse'")
}
https://www.zoho.com/invoice/api/v3/#Contacts_Get_a_Contact
func (c *API) GetContact(request interface{}, OrganizationID string, params map[string]zoho.Parameter) (data GetContactResponse, err error) {
package invoice
import (
	"fmt"
	zoho "github.com/schmorrison/Zoho"
)