class Sass::Tree::Visitors::Perform

def visit_comment(node)

Removes this node from the tree if it's a silent comment. 
def visit_comment(node)
  return [] if node.invisible?
  node.resolved_value = run_interp_no_strip(node.value)
  node.resolved_value.gsub!(/\\([\\#])/, '\1')
  node
end