def build_objects_by_subject
      @objects = []
      @objects_by_subject = {}

      @reader.statements_by_subject.each do |subject, statements|
        object = Grom::Node.new(statements, @decorators)
        @objects_by_subject[subject] = object
        @objects << object
      end

      self
    end
def build_objects_by_subject
      @objects = []
      @objects_by_subject = {}

      @reader.statements_by_subject.each do |subject, statements|
        object = Grom::Node.new(statements, @decorators)
        @objects_by_subject[subject] = object
        @objects << object
      end

      self
    end
Builds Grom::Node objects from n-triple data grouping by their subject.

 @return [Grom::Builder] an instance of self.