function isNonPositiveFinite( x ) {
	return Boolean( addon( x ) );
}
Tests if a numeric value is a nonpositive finite number.

@private
@param {number} x - value to test
@returns {boolean} boolean indicating whether the number is nonpositive finite

@example
var bool = isNonPositiveFinite( -2.0 );
// returns true

@example
var bool = isNonPositiveFinite( 5.0 );
// returns false