class Sass::Engine

def build_tree(parent, line, root = false)
  @line = line.index
  node_or_nodes = parse_line(parent, line, root)
  Array(node_or_nodes).each do |node|
    # Node is a symbol if it's non-outputting, like a variable assignment
    next unless node.is_a? Tree::Node
    node.line = line.index
    node.filename = line.filename
    append_children(node, line.children, false)
  end
  node_or_nodes
end