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: steward.rs
    path of file: ./repos/namada/crates/governance/src/pgf/storage
    
    the code of the file until where you have to start completion: use std::collections::HashMap;

use borsh::{BorshDeserialize, BorshSerialize};
use namada_core::address::Address;
use namada_core::dec::
    
    pub fn is_valid_reward_distribution(&self) -> bool {
        if self.reward_distribution.len() as u64 > REWARD_DISTRIBUTION_LIMIT {
            return false;
        }

        let mut sum = Dec::zero();
        for percentage in self.reward_distribution.values().cloned() {
            if percentage < Dec::zero() || percentage > Dec::one() {
                return false;
            }
            sum += percentage;
        }

        sum <= Dec::one()
    }