public class TxHandler {

	/* Creates a public ledger whose current UTXOPool (collection of unspent 
	 * transaction outputs) is utxoPool. This should make a defensive copy of 
	 * utxoPool by using the UTXOPool(UTXOPool uPool) constructor.
	 */
	public TxHandler(UTXOPool utxoPool) {
		// IMPLEMENT THIS
	}

	/* Returns true if 
	 * (1) all outputs claimed by tx are in the current UTXO pool, 
	 * (2) the signatures on each input of tx are valid, 
	 * (3) no UTXO is claimed multiple times by tx, 
	 * (4) all of tx’s output values are non-negative, and
	 * (5) the sum of tx’s input values is greater than or equal to the sum of   
	        its output values;
	   and false otherwise.
	 */

	public boolean isValidTx(Transaction tx) {
		// IMPLEMENT THIS
		return false;
	}

	/* Handles each epoch by receiving an unordered array of proposed 
	 * transactions, checking each transaction for correctness, 
	 * returning a mutually valid array of accepted transactions, 
	 * and updating the current UTXO pool as appropriate.
	 */
	public Transaction[] handleTxs(Transaction[] possibleTxs) {
		// IMPLEMENT THIS
		return null;
	}

}