function validate( opts, options ) {
	if ( !isObject( options ) ) {
		return new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
	}
	if ( hasOwnProp( options, 'alpha' ) ) {
		opts.alpha = options.alpha;
		if ( !isNumber( opts.alpha ) || isnan( opts.alpha ) ) {
			return new TypeError( format( 'invalid option. `%s` option must be a number. Option: `%s`.', 'alpha', opts.alpha ) );
		}
		if ( opts.alpha < 0.0 || opts.alpha > 1.0 ) {
			return new RangeError( format( 'invalid option. `%s` option must be a number on the interval: [0, 1]. Option: `%f`.', 'alpha', opts.alpha ) );
		}
	}
	return null;
}
Validates function options.

@private
@param {Object} opts - destination object
@param {Options} options - function options
@param {number} [options.alpha] - significance level
@returns {(Error|null)} null or an error object

@example
var opts = {};
var options = {
    'alpha': 0.6
};
var err = validate( opts, options );
if ( err ) {
    throw err;
}