• Assuming that this app should be able to accommodate multiple todo lists at one time. Thus I created a makeTodoList function that can be invoked multiple times for multiple todoLists.
• Assuming that when the instructions say, "The todoList maintains the integrity of the collection by returning only a copy of the collection anytime that a method returns all or a subset of it and by not allowing users/others objects to manipulate the values of todo objects directly.", it means that that todoList does not allow users/other objects to manipulate the values of todo objects directly OTHER THAN the add, delete and update operations.

Assuming the todo fields month and year are not required,

but if they are provided should be validated so that year >= current year (2019) and month is between 1 & 12

• Assuming todoData are objects with key value pairs for title, month, year, description with the values always being strings.
• Assuming that a todoData could NOT include completed field from the start.
• Assuming that the todo method isWithinMonthYear should return a boolean based on whether or not the todo's month value === given month value, and year value === given year value
• Assuming there is no validation needed for todoData being initialized or added to the program
• Assuming all inputs are the correct type and do not need to be validated

// change name of makeTodoList to todoList? // does returning undefined for todoList operations make sense?