calc intrinsic gas

 calcIntrinsic: encodedData => {
    const txFee = new BigNumber('21000')
    encodedData = hexToBytes(encodedData)

    let countNonZeros = 0
    let countZeros = 0

    for (let i = 0; i < encodedData.length; i++) {
      const dataElement = encodedData[i]
      if (dataElement == '0') {
        ++countZeros
      }
    }
    countNonZeros = encodedData.length - countZeros
    countZerosTotal = new BigNumber(countZeros.toString()).times(new BigNumber('4'))
    countNonZerosTotal = new BigNumber(countNonZeros.toString()).times(new BigNumber('16'))
    return txFee.plus(countZerosTotal).plus(countNonZerosTotal)
  },