Function validate_num_data_signatures 

fn validate_num_data_signatures(
    verification_method: &ConfigVerificationMethod,
) -> impl FnOnce(&Option<NumDataSignatures>, &()) -> Result + '_

Validates that the required number of data signatures matches the verification method.

Errors

Returns an error, if the verification_method is ConfigPlainMode and its number of fingerprint_matches is fewer than that of num_data_signatures.