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: lib.rs
    path of file: ./repos/diem/storage/accumulator/src
    
    the code of the file until where you have to start completion: // Copyright (c) The Diem Core Contributors
// SPDX-License-Identifier: Apache-2.0

#![forbid(unsafe_code)]

//! This module provides algorithms for accessing and updating a Merkle Accumulator structure
//! persisted
    
    fn get_proof(&self, leaf_index: u64) -> Result<AccumulatorProof<H>> {
        ensure!(
            leaf_index < self.num_leaves as u64,
            "invalid leaf_index {}, num_leaves {}",
            leaf_index,
            self.num_leaves
        );

        let siblings = self.get_siblings(leaf_index, |_p| true)?;
        Ok(AccumulatorProof::new(siblings))
    }