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: tangle.rs
    path of file: ./repos/bee/bee-tangle/src
    
    the code of the file until where you have to start completion: // Copyright 2020-2021 IOTA Stiftung
// SPDX-License-Identifier: Apache-2.0

use std::sync::atomic::{AtomicU32, Ordering};

use bee_block::{
    payload::milestone::{MilestoneId, MilestoneIndex, MilestonePayload},
    Block, BlockId,
};
use bee_runtime::resource::ResourceHandle;
use hashbrown::HashMap;
us
    
    pub fn insert(&self, block: &Block, block_id: &BlockId, metadata: &BlockMetadata) {
        self.storage
            .insert(block_id, block)
            .ok()
            .and_then(|()| {
                self.storage.insert_strict(block_id, metadata).ok()?;

                let block_id = *block_id;
                for &parent in block.parents().iter() {
                    self.storage
                        .insert(&(parent, block_id), &())
                        .unwrap_or_else(|e| warn!("Failed to update approvers for block {:?}", e));
                }
                Some(())
            })
            .unwrap_or_default()
    }