function ownProps( obj ) {
	var key;

	// NOTE: possibility of perf boost if key enumeration order is known (see http://stackoverflow.com/questions/18531624/isplainobject-thing).
	for ( key in obj ) {
		if ( !hasOwnProp( obj, key ) ) {
			return false;
		}
	}
	return true;
}
Tests that an object only has own properties.

@private
@param {Object} obj - value to test
@returns {boolean} boolean indicating if an object only has own properties