code: async function(senderAddr, senderPassphrase, recipient, amountInWei) {
      const stPrimeContractAddress = coreAddresses.getAddressForContract('stPrime')
        , StPrimeKlass = require(rootPrefix + '/lib/contract_interact/st_prime')
        , stPrime = new StPrimeKlass(stPrimeContractAddress)
      ;
  
      return stPrime.transfer(senderAddr, senderPassphrase, recipient, amountInWei, {returnType: 'txReceipt', tag: 'GasRefill'})
    }
docs: Transfer STPrime
  
  @param {string} senderAddr - address of user who is sending amount
  @param {string} senderPassphrase - sender address passphrase
  @param {string} recipient - address of user who is receiving amount
  @param {BigNumber} amountInWei - amount which is being transferred
  
  @return {promise<result>}