func (c *OutgoingCallerIDService) Create(ctx context.Context, data url.Values) (*CallerIDRequest, error) {
	id := new(CallerIDRequest)
	err := c.client.CreateResource(ctx, callerIDPathPart, data, id)
	return id, err
}
Create a new OutgoingCallerID. Note the ValidationCode is only returned in
response to a Create, you can't retrieve it later.

https://www.twilio.com/docs/api/rest/outgoing-caller-ids#list-post
package twilio
import (
	"context"
	"net/url"
)
const callerIDPathPart = "OutgoingCallerIds"
type OutgoingCallerIDService struct {
	client *Client
}
type OutgoingCallerID struct {
	Sid          string      `json:"sid"`
	FriendlyName string      `json:"friendly_name"`
	PhoneNumber  PhoneNumber `json:"phone_number"`
	AccountSid   string      `json:"account_sid"`
	DateCreated  TwilioTime  `json:"date_created"`
	DateUpdated  TwilioTime  `json:"date_updated"`
	URI          string      `json:"uri"`
}
type CallerIDRequest struct {
	AccountSid   string      `json:"account_sid"`
	PhoneNumber  PhoneNumber `json:"phone_number"`
	FriendlyName string      `json:"friendly_name"`
	ValidationCode string `json:"validation_code"`
	CallSid        string `json:"call_sid"`
}
type OutgoingCallerIDPage struct {
	Page
	OutgoingCallerIDs []*OutgoingCallerID `json:"outgoing_caller_ids"`
}