How to use the knex/lib/promise.method function in knex

inherits(Mocked, SQLite3);

Mocked.prototype.dialect = 'mocked';
Mocked.prototype.initDriver = function() {};
Mocked.prototype.initPool = function() {};
Mocked.prototype.initMigrator = function() {};

Mocked.prototype.initRunner = function() {
  require('./runner')(this);
};

Mocked.prototype.acquireConnection = Promise.method(function() {
  return {};
});

Mocked.prototype.releaseConnection = Promise.method(function() {});

module.exports = Mocked;

module.exports = function(client) {
  var _ = require('lodash');
  var Promise = require('knex/lib/promise');

  require('knex/lib/dialects/sqlite3/runner')(client);

  var SQLite3 = client.Runner;
  var inherits = require('util').inherits;

  function Mocked() {
    SQLite3.apply(this, arguments);
  }

  inherits(Mocked, SQLite3);

  Mocked.prototype._query = Promise.method(function(obj) {
    if (this.isDebugging()) {
      this.debug(obj);
    }

    return new Promise(function(resolver, rejecter) {
      tracker.queries.track(obj, resolver);
    });
  });

  Mocked.prototype._beginTransaction    = 'begin;';
  Mocked.prototype._commitTransaction   = 'commit;';
  Mocked.prototype._rollbackTransaction = 'rollback;';

  Mocked.prototype.processResponse = function(obj) {
    if (obj.output) {
      obj.result = obj.output.call(this, obj.result);

return this;
  };
}

inherits(Mocked, SQLite3);

Mocked.prototype.dialect = 'mocked';
Mocked.prototype.initDriver = function() {};
Mocked.prototype.initPool = function() {};
Mocked.prototype.initMigrator = function() {};

Mocked.prototype.initRunner = function() {
  require('./runner')(this);
};

Mocked.prototype.acquireConnection = Promise.method(function() {
  return {};
});

Mocked.prototype.releaseConnection = Promise.method(function() {});

module.exports = Mocked;