        so the new transaction will not be explicitly bip-125 replaceable (though it may
                         still be replaceable in practice, for example if it has unconfirmed ancestors which
                         are replaceable).
     "estimate_mode"     (string, optional, default=UNSET) The fee estimate mode, must be one of:
         "UNSET"
         "ECONOMICAL"
         "CONSERVATIVE"
   }

Result:
{
  "txid":    "value",   (string)  The id of the new transaction
  "origfee":  n,         (nume