Directed Acyclic Graph (DAG) representation for feature engineering workflows in Feast. This module is designed to remain abstracted and independent of Feast feature view business logic.

Core concepts include:

• context: ExecutionContext for managing feature view execution.
• node: DAGNode for representing operations in the DAG.
• value: DAGValue class for handling data passed between nodes.
• model: Model class for defining the dag data classes such as DAGFormat.
• plan: ExecutionPlan for executing the DAG.