class ActiveRecord::Associations::Preloader::ThroughAssociation

def through_scope
  scope = through_reflection.klass.unscoped
  options = reflection.options
  return scope if options[:disable_joins]
  values = reflection_scope.values
  if annotations = values[:annotate]
    scope.annotate!(*annotations)
  end
  if options[:source_type]
    scope.where! reflection.foreign_type => options[:source_type]
  elsif !reflection_scope.where_clause.empty?
    scope.where_clause = reflection_scope.where_clause
    if includes = values[:includes]
      scope.includes!(source_reflection.name => includes)
    else
      scope.includes!(source_reflection.name)
    end
    if values[:references] && !values[:references].empty?
      scope.references_values |= values[:references]
    else
      scope.references!(source_reflection.table_name)
    end
    if joins = values[:joins]
      scope.joins!(source_reflection.name => joins)
    end
    if left_outer_joins = values[:left_outer_joins]
      scope.left_outer_joins!(source_reflection.name => left_outer_joins)
    end
    if scope.eager_loading? && order_values = values[:order]
      scope = scope.order(order_values)
    end
  end
  cascade_strict_loading(scope)
end