Function anchor_for_parent_with_frontiers 

pub fn anchor_for_parent_with_frontiers<N, Provider>(
    parent_hash: B256,
    in_mem_chain: impl Iterator<Item = ExecutedBlock<N>>,
    partial_state_trie: BlockNumHash,
    finish: BlockNumHash,
    provider: &Provider,
) -> ProviderResult<AnchorForParent<N>>
where
    N: NodePrimitives,
    Provider: BlockNumReader + PruneCheckpointReader,

Returns the anchor block to use for the target parent and a chain of in-memory blocks using known durable frontiers.

Arguments

• parent: The block whose post-state is being targeted.
• in_mem_chain: Yields the in-memory blocks in the chain, starting at parent_hash.
• partial_state_trie: The durable state/trie frontier.
• finish: The durable Finish frontier.
• provider: Used to resolve the parent and check changeset availability.