Map Methods
        Method	Description
        new Map()	Creates a new Map object
        set()	Sets the value for a key in a Map
        get()	Gets the value for a key in a Map
        clear()	Removes all the elements from a Map
        delete()	Removes a Map element specified by a key
        has()	Returns true if a key exists in a Map
        forEach()	Invokes a callback for each key/value pair in a Map
        entries()	Returns an iterator object with the [key, value] pairs in a Map
        keys()	Returns an iterator object with the keys in a Map
        values()	Returns an iterator object of the values in a Map
        Property	Description
        size	Returns the number of Map elements   
        
        JavaScript Objects vs Maps
            Differences between JavaScript Objects and Maps:
            Object                                Map
            Not directly iterable               Directly iterable
            Do not have a size property	        Have a size property
            Keys must be Strings (or Symbols)	Keys can be any datatype
            Keys are not well ordered	        Keys are ordered by insertion
            Have default keys	                Do not have default keys