//    ('[' for IndexExpr, 'if' for IfStmt, etc.)
	Pos() Pos
	SetPos(Pos)
	aNode()
}

type node struct {
	// commented out for now since not yet used
	// doc  *Comment // nil means no comment(s) attached
	pos Pos
}

func (n *node) Pos() Pos       { return n.pos }
func (n *node) SetPos(pos Pos) { n.pos = pos }
func (*node) aNode()           {}

			// We should never get here. If we do, provide good diagnostic.
			return fmt.Errorf("format.Node internal error (%s)", err)
		}
		ast.SortImports(fset, file)

		// Use new file with sorted imports.
		node = file
		if cnode != nil {
			node = &printer.CommentedNode{Node: file, Comments: cnode.Comments}
		}
	}

	return config.Fprint(dst, fset, node)
}

// Source formats src in canonical gofmt style and returns the result