code: function isRekord(x)
  {
    return !!(x && x.Database && isFunction( x ) && x.prototype instanceof Model);
  }
docs: Determines whether the given variable is a Rekord object. A Rekord object is a
  constructor for a model and also has a Database variable. A Rekord object is
  strictly created by the Rekord function.
  
  ```javascript
  var Task = Rekord({
  name: 'task',
  fields: ['name', 'done', 'finished_at', 'created_at', 'assigned_to']
  });
  Rekord.isRekord( Task ); // true
  ```
  
  @memberof Rekord
  @param {Any} x
  The variable to test.
  @return {Boolean} -
  True if the variable is a Rekord object, otherwise false.