The usage of the function as shown in the following example is:
test:function(a,b){ return a*b; } 〈===〉 var test =function(a,b) { return a*b ;}
The way this function is written is that the map form in json in js has "key-value pairs"
Where test is the key function is the value
This way of writing is usually in a pair of "{ }"