You are provided with the following information about a bank system. A bank system contains data on customers (identified by name and address) and their accounts.
There are three type of accounts and each account has a balance and unique account number. The type of accounts is:
• Checking: this account is used for daily operations i. e. you can perform credit and debit transactions to deposit or withdraw an amount from the account. Bank charges transaction fee on each debit transaction.
• Savings which offers an interest rate. Bank pays an interest on lowest monthly balance and charges a transaction fee on each debit transaction. The money cannot be deposited or withdrawn from this account. It can only be transferred to/from checking account.
• Investments: this account is used to buy stocks. Stocks are bought at a certain quantity for a certain price (ticker) and bank applies commission on stock orders. The money cannot be deposited or withdrawn from this account. It can only be transferred to/from checking account.
Requirement:
• Identify possible classes to model the solution. (1 point)
• Identify possible relationships between those classes based upon the provided description. Also model the needed multiplicity. (2 points)
• Model possible attributes for each class based upon the given description. (1 point)
• Model possible operations for each class based upon the given description. (1 point)

This question involves a class named textfile that represents a text file. public class textfile { private string filename; private string filename; private arraylist words; // constructors not shown // postcondition: returns the number of bytes in this file public int filesize() { } // precondition: 0 < = index < words.size() // postcondition: removes numwords words from the words arraylist beginning at // index. public void deletewords(int index, int numwords) { } // precondition: 0 < = index < = words.size() // postcondition: adds elements from newwords array to words arraylist beginning // at index. pub lic voidaddwords(int index, string[] newwords) { } // other methods not shown } complete the filesize() method. the filesize() is computed in bytes. in a text file, each character in each word counts as one byte. in addition, there is a space in between each word in the words arraylist, and each of those spaces also counts as one byte. for example, suppose the words arraylist stores the following words: { mary had a little lamb; its fleece was white as snow. } the filesize() method would compute 4 + 3 + 1 + 6 + 5 + 4 + 6 + 3 + 5 + 2 + 5 as the sum of the lengths of each string in the arraylist. the value returned would be this sum plus 10, because there would also be 10 spaces in between the 11 words. complete the filesize() method below: // postcondition: returns the number of bytes in this file public int filesize() { }