code: function isValidWIF (key, network) {
  	try {
  	let dec = wif.decode(key);
  
  	if (network) {
  		return dec.version === network.wif
  	} else {
  		return true
  	}
  } catch (e) {
  	console.error(e);
  	return false
  }
  }
docs: Check if a WIF is valid for a specific CoinNetwork
  @param  {string} key - Base58 WIF Private Key
  @param  {CoinNetwork} network
  @return {Boolean}