def responsive_image_tag(piece, options = {}, breakpoints)
        srcset = generate_srcset(piece)
        sizes = generate_sizes(piece, breakpoints)
        # Let's just use an plain image_tag if responsive styles haven't been
        # generated. We'll test for :x2000 to determine if that's the case
        if piece.image.attachment.exists?(computed_style(piece, 'x2000'))
          image_tag(piece.image.url(default_style(piece, breakpoints)), options.merge(srcset: srcset, sizes: sizes))
        else
          image_tag(piece.image.url(:_medium), options)
        end
      end
def responsive_image_tag(piece, options = {}, breakpoints)
        srcset = generate_srcset(piece)
        sizes = generate_sizes(piece, breakpoints)
        # Let's just use an plain image_tag if responsive styles haven't been
        # generated. We'll test for :x2000 to determine if that's the case
        if piece.image.attachment.exists?(computed_style(piece, 'x2000'))
          image_tag(piece.image.url(default_style(piece, breakpoints)), options.merge(srcset: srcset, sizes: sizes))
        else
          image_tag(piece.image.url(:_medium), options)
        end
      end
Returns the actual image_tag