function isPropertyKey( value ) {
	return (
		isString( value ) ||
		isSymbol( value ) ||
		isNonNegativeInteger( value )
	);
}
Tests whether a value is a property key.

## Notes

-   A property key is either a string, symbol, or a nonnegative integer.

@param {*} value - value to test
@returns {boolean} boolean indicating whether value is a property key

@example
var bool = isPropertyKey( 'beep' );
// returns true

@example
var bool = isPropertyKey( 37 );
// returns true

@example
var bool = isPropertyKey( {} );
// returns false

@example
var bool = isPropertyKey( [] );
// returns false