code: function insertHexadecimalToByteArray (str, buffer, from) {
    for (let i = 0; i < str.length; i += 2) {
      buffer[from] = parseInt(str.substr(i, 2), 16)
      from++
    }
    return buffer
  }
docs: Encoder
  
  @param {string} str string to encode
  @param {Array} buffer buffer to place result to
  @param {number} from position to write from
  @returns {Array} modified buffer
  @private