ActiveRecord\HasMany::load PHP Method

    public function load(Model $model)
    {
        $class_name = $this->class_name;
        $this->set_keys(get_class($model));
        // since through relationships depend on other relationships we can't do
        // this initiailization in the constructor since the other relationship
        // may not have been created yet and we only want this to run once
        if (!isset($this->initialized)) {
            if ($this->through) {
                // verify through is a belongs_to or has_many for access of keys
                if (!($through_relationship = $this->get_table()->get_relationship($this->through))) {
                    throw new HasManyThroughAssociationException("Could not find the association {$this->through} in model " . get_class($model));
                }
                if (!$through_relationship instanceof HasMany && !$through_relationship instanceof BelongsTo) {
                    throw new HasManyThroughAssociationException('has_many through can only use a belongs_to or has_many association');
                }
                // save old keys as we will be reseting them below for inner join convenience
                $pk = $this->primary_key;
                $fk = $this->foreign_key;
                $this->set_keys($this->get_table()->class->getName(), true);
                $class = $this->class_name;
                $relation = $class::table()->get_relationship($this->through);
                $through_table = $relation->get_table();
                $this->options['joins'] = $this->construct_inner_join_sql($through_table, true);
                // reset keys
                $this->primary_key = $pk;
                $this->foreign_key = $fk;
            }
            $this->initialized = true;
        }
        if (!($conditions = $this->create_conditions_from_keys($model, $this->foreign_key, $this->primary_key))) {
            return null;
        }
        $options = $this->unset_non_finder_options($this->options);
        $options['conditions'] = $conditions;
        return $class_name::find($this->poly_relationship ? 'all' : 'first', $options);
    }