docs: function parseInteger( str, options ) {
  	var opts = {};
  	var err;
  	var v;
  
  	opts.radix = 10;
  	if ( arguments.length > 1 ) {
  		err = validate( opts, options );
  		if ( err ) {
  			return err;
  		}
  	}
  	v = parseInt( str, opts.radix );
  	if ( isnan( v ) ) {
  		return new TypeError( 'invalid value. Unable to parse string as an integer. Value: `' + str + '`.' );
  	}
  	return v;
  }