def each_instance_batch(options={}, &block)
        options = {:connection => self.connection}.merge(options)
        all.each_instance_batch(options, &block)
      end
Public: Like each_row_batch, but yields an array of instantiated model
objects to the block

Parameters: same as each_row

Example:
Post.each_instance_batch { |batch| Post.process_batch(batch) }

Returns the number of rows yielded to the block