How to use the mongodb-core.Cursor function in mongodb-core

const index = arguments.length - 1;
    const cb = arguments[index];

    if (typeof cb === "function") {
      arguments[index] = function() {
        if (trace) trace.end();
        return cb.apply(this, arguments);
      };
    }
  }

  return insertOriginal.apply(this, arguments);
};
//mongo _find 'Cursor' callback is the first parameter
let _findOriginal = mongo.Cursor.prototype._find;

mongo.Cursor.prototype._find = function() {
  // console.log("Node Reaction Agent - MongoDB - Find");
  if (arguments.length > 0) {
    let trace = NodeReactionAgent.createTrace(library, "Find");

    const cb = arguments[0];

    if (typeof cb === "function") {
      arguments[0] = function() {
        if (trace) trace.end();
        return cb.apply(this, arguments);
      };
    }
  }

"use strict";

var inherits = require('util').inherits
  , f = require('util').format
  , formattedOrderClause = require('./utils').formattedOrderClause
  , handleCallback = require('./utils').handleCallback
  , ReadPreference = require('./read_preference')
  , MongoError = require('mongodb-core').MongoError
  , Readable = require('stream').Readable || require('readable-stream').Readable
  , Define = require('./metadata')
  , CoreCursor = require('mongodb-core').Cursor
  , Map = require('mongodb-core').BSON.Map
  , CoreReadPreference = require('mongodb-core').ReadPreference;

/**
 * @fileOverview The **Cursor** class is an internal class that embodies a cursor on MongoDB
 * allowing for iteration over the results returned from the underlying query. It supports
 * one by one document iteration, conversion to an array or can be iterated as a Node 0.10.X
 * or higher stream
 *
 * **CURSORS Cannot directly be instantiated**
 * @example
 * var MongoClient = require('mongodb').MongoClient,
 *   test = require('assert');
 * // Connection url
 * var url = 'mongodb://localhost:27017/test';
 * // Connect using MongoClient

"use strict";

var inherits = require('util').inherits
  , f = require('util').format
  , formattedOrderClause = require('./utils').formattedOrderClause
  , handleCallback = require('./utils').handleCallback
  , ReadPreference = require('./read_preference')
  , MongoError = require('mongodb-core').MongoError
  , Readable = require('stream').Readable || require('readable-stream').Readable
  , Define = require('./metadata')
  , CoreCursor = require('mongodb-core').Cursor
  , Map = require('mongodb-core').BSON.Map
  , CoreReadPreference = require('mongodb-core').ReadPreference;

/**
 * @fileOverview The **Cursor** class is an internal class that embodies a cursor on MongoDB
 * allowing for iteration over the results returned from the underlying query. It supports
 * one by one document iteration, conversion to an array or can be iterated as a Node 0.10.X
 * or higher stream
 *
 * **CURSORS Cannot directly be instantiated**
 * @example
 * var MongoClient = require('mongodb').MongoClient,
 *   test = require('assert');
 * // Connection url
 * var url = 'mongodb://localhost:27017/test';
 * // Connect using MongoClient

"use strict";

var inherits = require('util').inherits
  , f = require('util').format
  , formattedOrderClause = require('./utils').formattedOrderClause
  , handleCallback = require('./utils').handleCallback
  , ReadPreference = require('./read_preference')
  , MongoError = require('mongodb-core').MongoError
  , Readable = require('stream').Readable || require('readable-stream').Readable
  , Define = require('./metadata')
  , CoreCursor = require('mongodb-core').Cursor
  , Map = require('mongodb-core').BSON.Map
  , CoreReadPreference = require('mongodb-core').ReadPreference;

/**
 * @fileOverview The **Cursor** class is an internal class that embodies a cursor on MongoDB
 * allowing for iteration over the results returned from the underlying query. It supports
 * one by one document iteration, conversion to an array or can be iterated as a Node 0.10.X
 * or higher stream
 *
 * **CURSORS Cannot directly be instantiated**
 * @example
 * var MongoClient = require('mongodb').MongoClient,
 *   test = require('assert');
 * // Connection url
 * var url = 'mongodb://localhost:27017/test';
 * // Connect using MongoClient

"use strict";

var inherits = require('util').inherits
  , f = require('util').format
  , formattedOrderClause = require('./utils').formattedOrderClause
  , handleCallback = require('./utils').handleCallback
  , ReadPreference = require('./read_preference')
  , MongoError = require('mongodb-core').MongoError
  , Readable = require('stream').Readable || require('readable-stream').Readable
  , Define = require('./metadata')
  , CoreCursor = require('mongodb-core').Cursor
  , Map = require('mongodb-core').BSON.Map
  , CoreReadPreference = require('mongodb-core').ReadPreference;

/**
 * @fileOverview The **Cursor** class is an internal class that embodies a cursor on MongoDB
 * allowing for iteration over the results returned from the underlying query. It supports
 * one by one document iteration, conversion to an array or can be iterated as a Node 0.10.X
 * or higher stream
 *
 * **CURSORS Cannot directly be instantiated**
 * @example
 * var MongoClient = require('mongodb').MongoClient,
 *   test = require('assert');
 * // Connection url
 * var url = 'mongodb://localhost:27017/test';
 * // Connect using MongoClient

"use strict";

var inherits = require('util').inherits
  , f = require('util').format
  , toError = require('./utils').toError
  , getSingleProperty = require('./utils').getSingleProperty
  , formattedOrderClause = require('./utils').formattedOrderClause
  , handleCallback = require('./utils').handleCallback
  , Logger = require('mongodb-core').Logger
  , EventEmitter = require('events').EventEmitter
  , ReadPreference = require('./read_preference')
  , MongoError = require('mongodb-core').MongoError
  , Readable = require('stream').Readable || require('readable-stream').Readable
  , Define = require('./metadata')
  , CoreCursor = require('mongodb-core').Cursor
  , Map = require('mongodb-core').BSON.Map
  , Query = require('mongodb-core').Query
  , CoreReadPreference = require('mongodb-core').ReadPreference;

/**
 * @fileOverview The **Cursor** class is an internal class that embodies a cursor on MongoDB
 * allowing for iteration over the results returned from the underlying query. It supports
 * one by one document iteration, conversion to an array or can be iterated as a Node 0.10.X
 * or higher stream
 *
 * **CURSORS Cannot directly be instantiated**
 * @example
 * var MongoClient = require('mongodb').MongoClient,
 *   test = require('assert');
 * // Connection url
 * var url = 'mongodb://localhost:27017/test';

"use strict";

var inherits = require('util').inherits
  , f = require('util').format
  , formattedOrderClause = require('./utils').formattedOrderClause
  , handleCallback = require('./utils').handleCallback
  , ReadPreference = require('./read_preference')
  , MongoError = require('mongodb-core').MongoError
  , Readable = require('stream').Readable || require('readable-stream').Readable
  , Define = require('./metadata')
  , CoreCursor = require('mongodb-core').Cursor
  , Map = require('mongodb-core').BSON.Map
  , CoreReadPreference = require('mongodb-core').ReadPreference;

/**
 * @fileOverview The **Cursor** class is an internal class that embodies a cursor on MongoDB
 * allowing for iteration over the results returned from the underlying query. It supports
 * one by one document iteration, conversion to an array or can be iterated as a Node 0.10.X
 * or higher stream
 *
 * **CURSORS Cannot directly be instantiated**
 * @example
 * var MongoClient = require('mongodb').MongoClient,
 *   test = require('assert');
 * // Connection url
 * var url = 'mongodb://localhost:27017/test';
 * // Connect using MongoClient

"use strict";

var inherits = require('util').inherits
  , f = require('util').format
  , formattedOrderClause = require('./utils').formattedOrderClause
  , handleCallback = require('./utils').handleCallback
  , ReadPreference = require('./read_preference')
  , MongoError = require('mongodb-core').MongoError
  , Readable = require('stream').Readable || require('readable-stream').Readable
  , Define = require('./metadata')
  , CoreCursor = require('mongodb-core').Cursor
  , Map = require('mongodb-core').BSON.Map
  , CoreReadPreference = require('mongodb-core').ReadPreference;

/**
 * @fileOverview The **Cursor** class is an internal class that embodies a cursor on MongoDB
 * allowing for iteration over the results returned from the underlying query. It supports
 * one by one document iteration, conversion to an array or can be iterated as a Node 0.10.X
 * or higher stream
 *
 * **CURSORS Cannot directly be instantiated**
 * @example
 * var MongoClient = require('mongodb').MongoClient,
 *   test = require('assert');
 * // Connection url
 * var url = 'mongodb://localhost:27017/test';
 * // Connect using MongoClient

'use strict';

const Transform = require('stream').Transform;
const PassThrough = require('stream').PassThrough;
const inherits = require('util').inherits;
const deprecate = require('util').deprecate;
const handleCallback = require('./utils').handleCallback;
const ReadPreference = require('mongodb-core').ReadPreference;
const MongoError = require('mongodb-core').MongoError;
const Readable = require('stream').Readable;
const CoreCursor = require('mongodb-core').Cursor;
const Map = require('mongodb-core').BSON.Map;
const executeOperation = require('./utils').executeOperation;

const count = require('./operations/cursor_ops').count;
const each = require('./operations/cursor_ops').each;
const hasNext = require('./operations/cursor_ops').hasNext;
const next = require('./operations/cursor_ops').next;
const toArray = require('./operations/cursor_ops').toArray;

/**
 * @fileOverview The **Cursor** class is an internal class that embodies a cursor on MongoDB
 * allowing for iteration over the results returned from the underlying query. It supports
 * one by one document iteration, conversion to an array or can be iterated as a Node 4.X
 * or higher stream
 *
 * **CURSORS Cannot directly be instantiated**