Class Features:  __init__(self, basic_rate, default_mins, rate_per_min, has_rollover): create/initialize instance
variables for all four non-self parameters. You can assume all arguments are valid and there
is no need to perform any checking.
 __str__: create/return a string as in this example:
"Basic˽rate:˽25.50,˽Default mins: ˽ ˽200,˽Rate/min:˽0.50,˽Rollover:˽Tru e"

add_phone(phone): Add the given phone line to the end of the list of phone lines. If there is already a phone in the plan by the same area code and number, do not append and return False. All updates made in this method change instance variables directly and the method returns None. Hint: Your Phone class's __eq__ method can help.
 remove_phone(phone): Remove the given phone line from the list of phone lines; remove calls that are only associated with the given phone (not any other phone of this plan) from the list of calls. A call is associated with a phone line if the line is either its caller or callee. If phone is not present in the list of phone lines, perform no removal and return False. All updates made in this method change instance variables directly and the method returns None. Hint: Your Phone class's __eq__ method can help.