isUndefined_.isUndefined(value) Returns true if value is undefined.

isNumber_.isNumber(object) Returns true if object is a Number (including NaN).

isObject_.isObject(value) Returns true if value is an Object. Note that JavaScript arrays and functions are objects

isBoolean_.isBoolean(object) Returns true if object is either true or false.

create_.create(prototype, props) Creates a new object with the given prototype, optionally attaching props as own properties

isArray_.isArray(object) Returns true if object is an Array.

isError_.isError(object) Returns true if object inherits from an Error.

invert_.invert(object) Returns a copy of the object where the keys have become the values and the values the keys. For this