Function charter_election_target 

pub fn charter_election_target(
    contract_id: &Identifier,
    document_type_name: &str,
    index_values: &[Value],
) -> Option<Identifier>

The contract a moderation election contends for: the single value of the contested index’s key, targetContractId, in any form validation accepts for an identifier (from protocol version 14 a contest’s index values are written as Value::Identifier anyway, see Index::extract_contested_values). None for every other contest, and for index values that do not name one contract, a base58 string included.