bench/lib/benchmark.js
function isArguments() {
    // lazy define
    isArguments = function(value) {
      return toString.call(value) == '[object Arguments]';
    };
    if (noArgumentsClass) {
      isArguments = function(value) {
        return hasKey(value, 'callee') &&
          !(propertyIsEnumerable && propertyIsEnumerable.call(value, 'callee'));
      };
    }
    return isArguments(arguments[0]);
  }
function isArguments() {
    // lazy define
    isArguments = function(value) {
      return toString.call(value) == '[object Arguments]';
    };
    if (noArgumentsClass) {
      isArguments = function(value) {
        return hasKey(value, 'callee') &&
          !(propertyIsEnumerable && propertyIsEnumerable.call(value, 'callee'));
      };
    }
    return isArguments(arguments[0]);
  }
function isArguments ( ) { // lazy define isArguments = function ( value ) { return toString . call ( value ) == '[object Arguments]' ; } ; if ( noArgumentsClass ) { isArguments = function ( value ) { return hasKey ( value , 'callee' ) && ! ( propertyIsEnumerable && propertyIsEnumerable . call ( value , 'callee' ) ) ; } ; } return isArguments ( arguments [ 0 ] ) ; }
Checks if a value is an `arguments` object.

@private
@param {Mixed} value The value to check.
@returns {Boolean} Returns `true` if the value is an `arguments` object, else `false`.
Checks if a value is an arguments object .