# File htree/doc.rb, line 56
    def initialize(children=[]) # :notnew:
      @children = children.dup.freeze
      unless @children.all? {|c| c.kind_of?(HTree::Node) and !c.kind_of?(HTree::Doc) }
        unacceptable = @children.reject {|c| c.kind_of?(HTree::Node) and !c.kind_of?(HTree::Doc) }
        unacceptable = unacceptable.map {|uc| uc.inspect }.join(', ')
        raise TypeError, "Unacceptable document child: #{unacceptable}"
      end
    end