You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: task.go
    path of file: ./repos/go-swagger/examples/task-tracker/models
    
    the code of the file until where you have to start completion: // Code generated by go-swagger; DO NOT EDIT.

package models

// This file was generated by the swagger tool.
// Editing this file m
    
func (m *TaskAttachmentsAnon) validateURL(formats strfmt.Registry) error {
	if swag.IsZero(m.URL) { // not required
		return nil
	}

	if err := validate.FormatOf("url", "body", "uri", m.URL.String(), formats); err != nil {
		return err
	}

	return nil
}