src/object/index.js
function (obj) {
        "use strict";

        if (Object.getPrototypeOf(obj) !== Object.prototype) {
            throw Error("obj must be an Object");
        }

        return Object.keys(obj)[0] || null;
    }
function (obj) {
        "use strict";

        if (Object.getPrototypeOf(obj) !== Object.prototype) {
            throw Error("obj must be an Object");
        }

        return Object.keys(obj)[0] || null;
    }
function ( obj ) { "use strict" ; if ( Object . getPrototypeOf ( obj ) !== Object . prototype ) { throw Error ( "obj must be an Object" ) ; } return Object . keys ( obj ) [ 0 ] || null ; }
Get first key of an object or null if it doesn't have keys
@param {Object} obj
@return {*}
@memberof object
Get first key of an object or null if it doesn t have keys