code: function _signersToAsn1(signers) {
    var ret = [];
    for(var i = 0; i < signers.length; ++i) {
      ret.push(_signerToAsn1(signers[i]));
    }
    return ret;
  }
docs: Map an array of signer objects to ASN.1 objects.
  
  @param signers an array of signer objects.
  
  @return an array of ASN.1 SignerInfos.