def with_tabs(i)
      old_tabs = haml_buffer.tabulation
      haml_buffer.tabulation = i
      yield
    ensure
      haml_buffer.tabulation = old_tabs
    end
def with_tabs(i)
      old_tabs = haml_buffer.tabulation
      haml_buffer.tabulation = i
      yield
    ensure
      haml_buffer.tabulation = old_tabs
    end
Sets the number of tabs the buffer automatically adds
 to the lines of the template,
 but only for the duration of the block.
 For example:

     %h1 foo
     - with_tabs(2) do
       %p bar
     %strong baz

 Produces:

     <h1>foo</h1>
         <p>bar</p>
     <strong>baz</strong>


 @param i [Fixnum] The number of tabs to use
 @yield A block in which the indentation will be `i` spaces