class RDoc::ClassModule

def merge(class_module)
  @parent      = class_module.parent
  @parent_name = class_module.parent_name
  other_document = parse class_module.comment_location
  if other_document then
    document = parse @comment_location
    document = document.merge other_document
    @comment = RDoc::Comment.from_document(document)
    @comment_location = document
  end
  cm = class_module
  other_files = cm.in_files
  merge_collections attributes, cm.attributes, other_files do |add, attr|
    if add then
      add_attribute attr
    else
      @attributes.delete attr
      @methods_hash.delete attr.pretty_name
    end
  end
  merge_collections constants, cm.constants, other_files do |add, const|
    if add then
      add_constant const
    else
      @constants.delete const
      @constants_hash.delete const.name
    end
  end
  merge_collections includes, cm.includes, other_files do |add, incl|
    if add then
      add_include incl
    else
      @includes.delete incl
    end
  end
  @includes.uniq! # clean up
  merge_collections extends, cm.extends, other_files do |add, ext|
    if add then
      add_extend ext
    else
      @extends.delete ext
    end
  end
  @extends.uniq! # clean up
  merge_collections method_list, cm.method_list, other_files do |add, meth|
    if add then
      add_method meth
    else
      @method_list.delete meth
      @methods_hash.delete meth.pretty_name
    end
  end
  merge_sections cm
  self
end