$($Java$)$ Assume that$$email$$is a String$$variable that has been assigned a string$$containing an email address, such as:

"joe@example.com"

Also assume that username is a String$$variable that has been declared. Write code that assigns the username part of the email address to the username variable. $($The username is the part of the address that appears before the @ symbol.$)$

For example, if the string "joe@example.com" has been assigned to the email variable, your code will assign "joe" to the username variable.