ArcGIS Pro 2.7 API Reference Guide
ProjectExtender Class
Members 

ArcGIS.Desktop.Core Namespace : ProjectExtender Class
Contains extension methods to extend Project.
Syntax
public static class ProjectExtender 
Public MustInherit NotInheritable Class ProjectExtender 
Inheritance Hierarchy

System.Object
   ArcGIS.Desktop.Core.ProjectExtender

Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

ProjectExtender Members
ArcGIS.Desktop.Core Namespace