Entity Framework Question:

POCO Proxy is a runtime proxy class of POCO entity. POCO entity becomes POCO Proxy entity if it meets certain requirements to enable lazy loading proxy and instant change tracking. It adds some methods at runtime to your POCO class which does instant change tracking and lazy loading stuff.
POCO entity should meet the following requirement to become POCO proxy:

A custom data class must be declared with public access.
A custom data class must not be sealed (NotInheritable in Visual Basic)
A custom data class must not be abstract (MustInherit in Visual Basic).
A custom data class must have a public or protected constructor that does not have parameters.
The class cannot implement the IEntityWithChangeTracker or IEntityWithRelationships interfaces because the proxy classes implement these interfaces.
The ProxyCreationEnabled option must be set to true.
Each navigation property must be declared as public, virtual