function check() {
	var k;
	if ( typeOf( win ) === 'undefined' ) {
		return false;
	}
	for ( k in win ) { // eslint-disable-line guard-for-in
		try {
			if (
				indexOf( EXCLUDED_KEYS, k ) === -1 &&
				hasOwnProp( win, k ) &&
				win[ k ] !== null &&
				typeOf( win[ k ] ) === 'object'
			) {
				isConstructorPrototype( win[ k ] );
			}
		} catch ( err ) { // eslint-disable-line no-unused-vars
			return true;
		}
	}
	return false;
}
Determines whether an environment throws when comparing to the prototype of a value's constructor (e.g., [IE9][1]).

[1]: https://stackoverflow.com/questions/7688070/why-is-comparing-the-constructor-property-of-two-windows-unreliable

@private
@returns {boolean} boolean indicating whether an environment is buggy