synced_headers_grandpa_info: RuntimeDescriptor<[], {
    finality_proof: {
        commit: {
            precommits: {
                id: FixedSizeBinary<32>;
                precommit: {
                    target_hash: FixedSizeBinary<32>;
                    target_number: number;
                };
                signature: FixedSizeBinary<64>;
            }[];
            target_hash: FixedSizeBinary<32>;
            target_number: number;
        };
        round: bigint;
        votes_ancestries: {
            digest: DigestItem[];
            extrinsics_root: FixedSizeBinary<32>;
            number: number;
            parent_hash: FixedSizeBinary<32>;
            state_root: FixedSizeBinary<32>;
        }[];
    };
    new_verification_context?: {
        authorities: [FixedSizeBinary<32>, bigint][];
        set_id: bigint;
    };
}[]>

Returns the justifications accepted in the current block.