capture_erb_with_buffer

# File actionpack/lib/action_view/helpers/capture_helper.rb, line 106
        def capture_erb_with_buffer(buffer, *args, &block)
          pos = buffer.length
          block.call(*args)
        
          # extract the block 
          data = buffer[pos..-1]
        
          # replace it in the original with empty string
          buffer[pos..-1] = ''
        
          data
        end