code: function(database, field, options)
    {
      applyOptions( this, options, this.getDefaults( database, field, options ) );
  
      this.database = database;
      this.name = field;
      this.options = options;
      this.initialized = false;
      this.property = this.property || (indexOf( database.fields, this.name ) !== false);
      this.discriminated = !isEmpty( this.discriminators );
  
      if ( this.discriminated )
      {
        if ( !Polymorphic )
        {
          throw 'Polymorphic feature is required to use the discriminated option.';
        }
  
        Class.props( this, Polymorphic );
      }
  
      this.setReferences( database, field, options );
    }
docs: Initializes this relation with the given database, field, and options.
  
  @param  {Rekord.Database} database [description]
  @param  {String} field    [description]
  @param  {Object} options  [description]